RFLP Analysis (rflp + analysis)

Distribution by Scientific Domains


Selected Abstracts


Geomicrobiology of deep-sea deposits: estimating community diversity from low-temperature seafloor rocks and minerals

GEOBIOLOGY, Issue 2 2003
Daniel R. Rogers
ABSTRACT The role of deep-sea microbial communities in the weathering of hydrothermal vent deposits is assessed using mineralogical and molecular biological techniques. The phylogenetic diversity of varied deep-sea bare rock habitats associated with the oceanic spreading centre at the Juan de Fuca Ridge was accessed using restriction fragment length polymorphism (RFLP) and rDNA sequencing. The mineralogical composition of the deposits used for phylogenetic analysis was determined by X-ray diffraction in order to determine the proportion and composition of sulphide minerals, and to determine degree of alteration associated with each sample. RFLP analyses resulted in 15 unique patterns, or Operational Taxonomic Units (OTUs). Most environments examined were dominated by only one or two OTUs, which often comprised approximately 60% of the rDNA clones generated from that environment. Only one environment, the Mound, had a representative rDNA clone from every OTU identified in this study. For one other environment, ODP sediments, rDNA clones were all contained in a single OTU. The diversity of the microbial community is found to decrease with decreasing reactivity of the sulphide component in the samples and with increasing presence of alteration products. Phylogenetic analyses reveal that OTUs contain representatives of the epsilon-, beta- and gamma-subdivisions of the Proteobacteria. OTU1, which dominates clone libraries from every environment and is increasingly dominant with increasing rock alteration, is closely related to a group of chemolithoautotrophic iron-oxidizing bacteria that have been recently isolated from the deep sea. The apparent abundance and widespread distribution within the samples examined of the putative iron-oxidizing bacteria that may be represented by OTU1 suggests that this physiological group could play an important role in rock-weathering and carbon fixation at the seafloor. [source]


Oxidative DNA damage in gastric cancer: CagA status and OGG1 gene polymorphism

INTERNATIONAL JOURNAL OF CANCER, Issue 1 2008
Fabio Farinati
Abstract Oxidative DNA damage is thought to play an important part in the pathogenesis of H. pylori -induced mucosal damage. 8-OHdG is a sensitive marker of DNA oxidation and is repaired by a polymorphic glycosylase (OGG1) more effectively than by OGG1 -Cys326. The aims of this study were to ascertain the respective roles of H. pylori, cagA status and OGG1 polymorphism in determining 8-OHdG levels in benign and premalignant stomach diseases and in gastric cancer (GC). The study involved 50 GC patients (for whom both neoplastic tissue and surrounding mucosa were available), 35 with intestinal metaplasia and atrophy (IMA) and 43 controls. H. pylori and cagA status were determined by histology and polymerase chain reaction for urease and cagA. 8-OHdG was assayed using HPLC with an electrochemical detector (HPLC-ED). The OGG1 1245C,G transversion was identified using RFLP analyses. 8-OHdG levels were significantly higher in GC, with no differences in relation to H. pylori or cagA status. OGG1 polymorphism was documented in 34% of GC (15 Ser/Cys, 2 Cys/Cys). OGG1 1245C,G polymorphism was detected in 54% of IMA patients, but only 16% of controls (p = 0.0004) and coincided with significantly higher 8-OHdG levels. In the multivariate analysis, 8-OHdG levels were predicted by histotype and OGG1 status. OGG1 1245C,G polymorphism was common in both GC and IMA, but very rare in controls, and correlated more closely with 8-OHdG levels than do H. pylori infection or cagA status. © 2008 Wiley-Liss, Inc. [source]


GENETIC DIVERGENCE CORRELATES WITH MORPHOLOGICAL AND ECOLOGICAL SUBDIVISION IN THE DEEP-WATER ELK KELP, PELAGOPHYCUS PORRA (PHAEOPHYCEAE)

JOURNAL OF PHYCOLOGY, Issue 5 2000
Kathy Ann Miller
Pelagophycus porra (Leman) Setchell has a narrow distribution confined to deep water from the Channel Islands off the southern California coast to central Baja California, Mexico. Distinct morphotypes are consistently correlated with distinctive habitats, that is, windward exposures characterized by strong water motion and rocky substrates, and sheltered areas with soft substrates found on the lee sides of the islands. We tested the hypothesis that morphologically and ecologically distinct forms reflect genetically distinct stands. Individuals representing populations from three islands and the mainland were compared using RFLP analyses of the nuclear rDNA internal transcribed spacers (ITS1 and ITS2), chloroplast trnL (UAA) intron sequences, and random amplified polymorphic DNA (RAPDs). No variation was found in a survey of 20 restriction sites of ITS1 (ca. 320 base pair [bp]) and ITS2 (ca. 360 bp) among individuals from six populations. Likewise, comparisons of trnL intron (241 bp) sequences among nine individuals from seven populations were identical with the exception of a CATAGT insert in two adjacent stands. A RAPD analysis of 24 individuals from nine populations (4 windward and 5 leeward) using 16 primers generated 166 bands. Thirty-eight percent of the bands did not vary, 16% were unique to a given individual, and 46% were variable. Neighbor joining analysis produced a well-resolved tree with moderately high bootstrap support in which windward and leeward populations were easily distinguished. The lack of divergence in both the fast evolving nuclear rDNA-ITS and the chloroplast trnL intron does not support the morphotypes as different species. However, the compartmentalized differentiation shown in the RAPD data clearly points to isolation. This, and previous ecological studies that demonstrate habitat specificity suggest that leeward stands probably comprise a species in statu nascendi. [source]


Multigene analysis for differentiation of aster yellows phytoplasmas infecting carrots in Serbia

ANNALS OF APPLIED BIOLOGY, Issue 2 2009
B. Duduk
Abstract During a survey of large carrot fields in Serbia, plants showing leaf reddening and/or yellowing, adventitious shoot production and reduction in taproot size and quality were observed in a low percentage of plants. To verify phytoplasma association with the described symptoms and to carry out pathogen differentiation, PCR assays followed by restriction fragment length polymorphism (RFLP) analyses and/or sequencing of phytoplasma 16Sr DNA and ribosomal protein genes l22 and s3, tuf, putative aa kinase plus ribosomal recycling factor genes and DNA helicase gene were carried out. Phytoplasmas belonging to 16SrI-A and 16SrI-B ribosomal subgroups and to rpI-A and rpI-B ribosomal protein subgroups, respectively, were identified by RFLP analyses in 13 of 15 symptomatic plants tested. No amplification was obtained with non-symptomatic carrot samples. The identification was confirmed by sequence analyses of the phytoplasma genes studied. In two carrot samples, presence of interoperon sequence heterogeneity was detected and phytoplasma strains were identified as belonging to 16SrI group but were not assigned to any 16S rRNA or ribosomal protein subgroup. This research allowed the first molecular identification of phytoplasmas infecting carrot in Serbia using several molecular markers, and it indicates that under field conditions in non-epidemic outbreaks a certain amount of genetic mutation may occur in conserved genes of these prokaryotes. [source]


Caucasian patients with type 2 diabetes mellitus have elevated levels of monocyte chemoattractant protein-1 that are not influenced by the ,2518 A,G promoter polymorphism

DIABETES OBESITY & METABOLISM, Issue 5 2005
B. Zietz
Aim:, To investigate the association of serum levels and the ,2518 A,G promoter polymorphism of the gene for chemokine monocyte chemoattractant protein-1 (MCP-1), a major chemoattractant of monocytes and activated lymphocytes, with metabolic parameters as well as insulin, leptin and the cytokines tumour necrosis factor-, (TNF-,) and interleukin-6 (IL-6) in 534 Caucasian patients with type 2 diabetes mellitus. Methods:, MCP-1 concentrations were measured by enzyme-linked immunosorbent assay. MCP-1 genotyping was performed by RFLP analysis in a subset of 426 patients. Results:, Two hundred and thirty-one (54.2%) patients were homozygous for the wildtype allele (AA), 156 (36.6%) were heterozygous (AG) and 39 (9.2%) were homozygous for the mutated allele (GG). Allelic frequency was similar to non-diabetic populations (wildtype allele A: 0.73; mutated allele G: 0.27). MCP-1 mean concentrations and percentiles were substantially higher in non-diabetic populations but were not influenced by the genotype (AA: 662.0 ± 323.0 pg/ml; AG: 730.6 ± 491.4 pg/ml; GG: 641.2 ± 323.8 pg/ml). MCP-1 serum levels and genotypes were only marginally related to hormones (insulin and leptin) and cytokines (TNF-, and IL-6). Conclusions:, This is the first study providing MCP-1 levels, percentiles and genotype frequency in a large and representative cohort of patients with type 2 diabetes mellitus. Compared to the literature, MCP-1 levels were found to be substantially higher in patients with type 2 diabetes mellitus. In contrast, genotype frequencies were similar compared to those in non-diabetic patients and were not related to MCP-1 levels. The mechanisms behind these elevated MCP-1 serum levels in type 2 diabetes are not to be explained by simple associations with hormones, cytokines or genotypes. [source]


Identification of economically important Liriomyza species by PCR-RFLP analysis,

EPPO BULLETIN, Issue 1 2005
L. F. F. Kox
Only adult males of Liriomyza bryoniae, L. huidobrensis, L. sativae and L. trifolii can be identified with certainty on basis of their genitalia. Female adults, pupae and larvae can only be identified on the level of groups of species (L. bryoniae and L. huidobrensis vs. L. sativae and L. trifolii). Species identification in all developmental stages is possible using molecular biological techniques. Our method is a PCR amplification of a 790-bp fragment of mitochondrial cytochrome oxidase II (COII) DNA followed by RFLP analysis. The method was tested on single larvae, pupae and adults and proved to be applicable to these three life stages. The specificity of the assay was assessed by comparing the results of the PCR-RFLP analysis with those of morphological analysis using 60 Liriomyza specimens. Molecular and morphological identification agreed for all specimens analysed. PCR-RFLP is a powerful diagnostic tool for rapid and reliable identification of all life stages of economically important Liriomyza species. [source]


Haplotype Frequency Distribution in Northeastern European Saduria entomon (Crustacea: Isopoda) Populations.

INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 6 2003
A Phylogeographic Approach
Abstract The distribution pattern of mtDNA haplotypes in distinct populations of the glacial relict crustacean Saduria entomon was examined to assess phylogeographic relationships among them. Populations from the Baltic, the White Sea and the Barents Sea were screened for mtDNA variation using PCR-based RFLP analysis of a 1150 bp fragment containing part of the CO I and CO II genes. Five mtDNA haplotypes were recorded. An analysis of geographical heterogeneity in haplotype frequency distributions revealed significant differences among populations. The isolated populations of S. entomon have diverged since the retreat of the last glaciation. The geographical pattern of variation is most likely the result of stochastic (founder effect, genetic drift) mechanisms and suggests that the haplotype differentiation observed is probably older than the isolation of the Baltic and Arctic seas. [source]


Molecular Characterization and Potential Insect Vector of a Phytoplasma Associated with Garden Beet Witches' Broom in Yazd, Iran

JOURNAL OF PHYTOPATHOLOGY, Issue 4 2007
A. Mirzaie
Abstract In 2002, garden beet witches' broom (GBWB) phytoplasma was detected for the first time in garden beet plants (Beta vulgaris L. ssp. esculenta) in Yazd, Iran. Nested polymerase chain reaction (PCR) and restriction fragment length polymorphic (RFLP) analysis of PCR-amplified phytoplasma 16S rDNA were employed for the detection and identification of the phytoplasma associated with garden beet. A phytoplasma belonging to subgroup 16SrII-E, in the peanut witches' broom group (16SrII), was detected in infected plants. Asymptomatic plant samples and the negative control yielded no amplification. The result of analysis of the nucleotide sequence of a 1428 bp fragment of 16S rDNA gene from GBWB phytoplasma (GenBank accession number DQ302722) was basically consistent with the classification based on RFLP analysis, in which GBWB phytoplasma clustered with phytoplasmas of the 16SrII-E subgroup. A search for a natural phytoplasma vector was conducted in Yazd in 2004, in an area where garden beet crops had been affected since 2002. The associated phytoplasma was detected in one leafhopper species, Orosius albicinctus, commonly present in this region. The leafhopper O. albicinctus was used in transmission tests to determine its vector status for the phytoplasma associated with GBWB. Two of eight plants that had been fed on by O. albicinctus, showed mild symptoms of GBWB including stunting and reddening of midveins. A phytoplasma was detected in the two symptomatic test plants by PCR using universal primers and it was identified by RFLP as the GBWB phytoplasma. This finding suggests O. albicinctus is a vector of the GBWB phytoplasma. [source]


Molecular identification of five commercial flatfish species by PCR,RFLP analysis of a 12S rRNA gene fragment

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2003
Angel S Comesaña
Abstract Refrigerated or frozen fillets of commercial flatfish species are sometimes mislabelled, and identification of those products is needed to avoid fraudulent substitution. Molecular identification of five commercial flatfish species (order Pleuronectiformes), ie Lepidorhombus whiffiagonis (megrim), Platichthys flesus (flounder), Reinhardtius hippoglossoides (Greenland halibut), Scophthalmus maximus (turbot) and Solea vulgaris (= S solea) (sole), has been carried out on the basis of the amplification of an approximately 433 bp segment from the mitochondrial 12S rRNA gene using the polymerase chain reaction (PCR) and universal primers. Direct DNA sequencing from two PCR products for each flatfish species was carried out, and sequences were used to select six restriction enzymes. PCR products of 15 individuals of each species were cut with each enzyme, resulting in species-specific restriction fragment length polymorphism (RFLP). The five flatfish species could be identified by application of the restriction enzyme AluI as well as by using different combinations of a pair of enzymes, ie DdeI and either AciI or MwoI. No intraspecific genetic polymorphism was found for any of the six enzymes. Results confirmed the usefulness of this technique to distinguish and genetically characterise refrigerated or frozen pieces of these five flatfish species. Copyright © 2003 Society of Chemical Industry [source]


Evolutionary assessment of Artemia tibetiana (Crustacea, Anostraca) based on morphometry and 16S rRNA RFLP analysis

JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 3 2005
A. D. Baxevanis
Abstract Over the last few years, molecular-based assays in the genus Artemia have considerably enriched prior systematic assessments based on morphometry. For the first time, morphometric and 16S rRNA PCR-RFLP analyses on all type-locality bisexual species of the genus have been employed here. Emphasis was put on the Asian species (Artemia urmiana, A. tibetiana, A. sinica) where patterns of divergence and reproductive isolation are rather discrete, and especially on A. tibetiana for which recent reports have questioned its specific status. Discriminant analysis of morphometric characters has shown significant differentiation among species. Classification scores were 99.4 and 100% for males and females, respectively. Mitochondrial DNA RFLP patterns have given indications for lower, albeit similar patterns of differentiation compared with those obtained by morphometry. Artemia tibetiana and A. urmiana are mitochondrially indistinguishable which is suggestive of recent ancestry. Our data, in conjunction with past evidence, are supportive of a significant amount of divergence between A. tibetiana and A. sinica. Morphometric and molecular assays can be reciprocally informative provided theory and patterns of speciation are incorporated into systematic assessments. Résumé Ces dernières années, les outils moléculaires utilisés dans l'étude du genre Artemia ont considèrablement enrichi les analyses systématiques antérieures basées sur la morphométrie. Pour la première fois, des analyses morphométriques et des analyses PCR-RFLP de l'ARN ribosomique 16S ont été effectuées pour toutes les espèces amphigoniques d'Artemia venant des localités types. Dans cette étude, nous nous sommes concentrés sur les espèces asiatiques (A. urmiana, A. tibetiana, A. sinica), qui présentent des traits de divergence et un isolement reproductif assez singuliers, et tout particulièrement sur l'A. tibetiana dont le statut d'espèce à part entière a été mis en doute dans de récentes études. Une analyse discriminante des caractéristiques morphométriques a révélé une différenciation importante parmi les espèces. Pour les mâles et les femelles, les scores de classification étaient respectivement de 99,4% et 100%. Les profils RFLP de l'ADN mitochondrial ont montré une différenciation similaire à celle observée grâce à l'analyse morphométrique. L'ADN mitochondrial de l'A. tibetiana est indifférenciable de celui de l'A. urmiana, ce qui suggère que ces deux espèces ont récemment divergé. Nos données, combinées à celles recueillies par le passé, indiquent une grande divergence entre l'A. tibetiana et l'A. sinica. Les analyses morphométriques et moléculaires peuvent se compléter à condition de tenir compte de la théorie de la spéciation et des modèles de spéciation durant les analyses systématiques. [source]


Intraspecific variation and population structure of the German cockroach, Blattella germanica, revealed with RFLP analysis of the non-transcribed spacer region of ribosomal DNA

MEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2007
D. V. MUKHA
Abstract Little information is available on genetic variation within and between populations of pest cockroaches. In this study, intraspecific HindIII polymorphism was investigated in the German cockroach, Blattella germanica (Linnaeus) (Dictyoptera, Blattaria: Blattellidae), using restriction fragment length polymorphisms (RFLP) of the non-transcribed spacer (NTS) region of ribosomal DNA (rDNA). Individual male insects were collected from infestations at three different pig farms. Each population was characterized by HindIII restriction fragment frequencies and haplotype (a particular X-chromosome pattern) frequencies. The inheritance of the X-chromosome HindIII rDNA patterns over 12 generations (3 years) follows Mendelian patterns, and the stability of this polymorphic marker indicates infrequent genetic recombination of variable sites. Although pairwise genetic distance measures were uncorrelated with geographical distance, the pattern of genetic differentiation of the three cockroach populations suggests that human-mediated transport of cockroaches is an important force in shaping the population genetic structure of cockroach infestations, at least at the regional scale of 10,100 km. Sequence variation in the ribosomal NTS is a useful marker, and RFLP of rDNA is a simple, robust and reproducible technique for differentiating recently diverged cockroach populations. [source]


Distribution and diversity of rhizobia nodulating agroforestry legumes in soils from three continents in the tropics

MOLECULAR ECOLOGY, Issue 4 2003
Abdullah Bala
Abstract The natural rhizobial populations of Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala and Sesbania sesban were assessed in soils from nine sites across tropical areas of three continents. The rhizobial population size varied from undetectable numbers to 1.8 × 104 cells/g of soil depending on the trap host and the soil. Calliandra calothyrsus was the most promiscuous legume, nodulating in eight soils, while S. sesban nodulated in only one of the soils. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analyses of the 16S rRNA gene and the internally transcribed spacer (ITS) region between the 16S and 23S rRNA genes were used to assess the diversity and relative abundance of rhizobia trapped from seven of the soils by C. calothyrsus, G. sepium and L. leucocephala. Representatives of the 16S rRNA RFLP groups were also subjected to sequence analysis of the first 950 base pairs of the 16S rRNA gene. Eighty ITS groups were obtained, with none of the ITS types being sampled in more than one soil. RFLP analysis of the 16S rRNA yielded 23 ,species' groups distributed among the Rhizobium, Mesorhizobium, Sinorhizobium and Agrobacterium branches of the rhizobial phylogenetic tree. The phylogeny of the isolates was independent of the site or host of isolation, with different rhizobial groups associated with each host across the soils from widely separated geographical regions. Although rhizobial populations in soils sampled from the centre of diversity of the host legumes were the most genetically diverse, soil acidity was highly correlated with the diversity of ITS types. Our results support the hypothesis that the success of these tree legumes in soils throughout the tropics is the result of their relative promiscuity (permissiveness) allowing nodulation with diverse indigenous rhizobial types. [source]


Prevalence of factor V G1691A (factor V-Leiden) and prothrombin G20210A gene mutations in a recurrent miscarriage population

AMERICAN JOURNAL OF HEMATOLOGY, Issue 4 2002
Ramzi R. Finan
Abstract Factor V G1691A (FV-Leiden) and prothrombin G20210A mutations are major inherited risk factors for venous thrombosis. Recently, it was suggested that both mutations, through stimulation of venous and placental thrombosis events, were strongly associated with recurrent idiopathic miscarriages, although other studies disputed such a link. The aim of this study was to determine the prevalence of prothrombin G20210A and factor V G1691A (R506Q, FV-Leiden) mutations in women with recurrent idiopathic abortions and to recommend management for high-risk mutation carriers. One hundred ten women with two or more consecutive unexplained first-trimester miscarriages (mean age ± SD, 32.3 ± 5.3) were compared to 67 parous women with uncomplicated pregnancies (mean age ± SD, 33.9 ±7.3) (P = 0.134) from the same ethnic background. The presence or absence of the prothrombin G20210A and FV-Leiden mutations was assessed by PCR and RFLP analysis, using HindIII and MnlI digestion, respectively. In women with primary habitual abortion, 45 (40.91%) carried the FV-Leiden mutation, of whom 7 were in the homozygote and 38 were in the heterozygote states, and 15 (13.64%) carried the prothrombin G20210A mutation all as heterozygotes, compared to 16.42% and 2.99% carrier rates among controls, respectively, all of whom were heterozygote carriers. Of the other risk factors analyzed, smoking (OR 1.76; 95% CI = 0.79,3.94) was more prevalent in habitual aborters compared to controls. Both FV-Leiden and factor II G20210A mutations are major inherited risk factor associated with primary recurrent miscarriages. Women with a family or personal history of thrombosis should be screened before or early in the pregnancy for FV-Leiden and factor II G20210A mutations. Am. J. Hematol. 71:300,305, 2002. © 2002 Wiley-Liss, Inc. [source]


A new DNA extraction method for high-throughput marker analysis in a large-genome species such as Triticum aestivum

PLANT BREEDING, Issue 4 2001
N. Stein
Abstract Gene mapping and marker-assisted selection in complex, polyploid genomes still relies strongly on restriction fragment length polymorphism (RFLP) analysis, as conversion of RFLP to polymerase chain reaction (PCR) markers can be very difficult. DNA extraction in amounts suitable for RFLP analysis represents the most time-consuming and labour-intensive step in molecular marker analysis of plant populations. In this paper, a new flexible method for plant DNA extraction is presented. It allows a high-throughput of samples in a short time without the need for freezing or lyophilizing the plant material. The method allows the isolation of genomic DNA with a yield of 100 ,g for a minimal amount of 200 mg of leaf material. This is sufficient for work with large-genome plant species such as hexaploid wheat, where 20 ,g of genomic DNA are required for a single RFLP analysis. [source]


ORIGINAL ARTICLE: Uterine Leiomyoma is Associated with a Polymorphism in the Interleukin 1-, Gene

AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 2 2009
Detlef Pietrowski
Problem, To investigate whether polymorphisms in the interleukin-1, (IL-1,) gene are associated with uterine leiomyoma. Method of study, Case,control study in a collective of 131 patients and 280 controls. Genotyping of the IL-1,-511 and IL-1,-3954 polymorphism was performed by PCR amplification and subsequent RFLP analysis. Results, A significant difference in the allele frequencies of the IL-1,-511 C[source]


Mitochondrial DNA variability in Poles and Russians

ANNALS OF HUMAN GENETICS, Issue 4 2002
B. A. MALYARCHUK
Mitochondrial DNA (mtDNA) sequence variation was examined in Poles (from the Pomerania-Kujawy region; n = 436) and Russians (from three different regions of the European part of Russia; n = 201), for which the two hypervariable segments (HVS I and HVS II) and haplogroup-specific coding region sites were analyzed. The use of mtDNA coding region RFLP analysis made it possible to distinguish parallel mutations that occurred at particular sites in the HVS I and II regions during mtDNA evolution. In total, parallel mutations were identified at 73 nucleotide sites in HVS I (17.8%) and 31 sites in HVS II (7.73%). The classification of mitochondrial haplotypes revealed the presence of all major European haplogroups, which were characterized by similar patterns of distribution in Poles and Russians. An analysis of the distribution of the control region haplotypes did not reveal any specific combinations of unique mtDNA haplotypes and their subclusters that clearly distinguish both Poles and Russians from the neighbouring European populations. The only exception is a novel subcluster U4a within subhaplogroup U4, defined by a diagnostic mutation at nucleotide position 310 in HVS II. This subcluster was found in common predominantly between Poles and Russians (at a frequency of 2.3% and 2.0%, respectively) and may therefore have a central-eastern European origin. [source]


Genetic characterization and gonad development of artificially produced interspecific hybrids of the abalones, Haliotis discus discus Reeve, Haliotis gigantea Gmelin and Haliotis madaka Habe

AQUACULTURE RESEARCH, Issue 5 2008
Faruq Ahmed
Abstract Hybridization among abalone species has been suggested as a possible means to increase their growth rates for aquaculture. As a first step to test the usefulness of the hybrids of Japanese abalone species (Haliotis discus discus, Haliotis gigantea and Haliotis madaka) for aquaculture, we characterized the genetic background and gonad development of hybrids that were produced by artificial insemination. The hybrid status of the resulting offspring was confirmed by assaying 14 allozymes and by RFLP analysis of the 16s rRNA and cytochrome oxidase I (COI) regions of mtDNA using 13 restriction enzymes. Histological examination of the gonads of the hybrids was conducted in comparison with those of the parental species. Cross-breeding among the three species was conducted successfully in all combinations although with lower fertilization rates (means of 1.3,60.8%) than the parental species (34.3,90%). Crosses between H. discus discus and H. madaka had higher fertilization rates (22.4,60.8%) than those involving H. gigantea (1.3,19.9%). The hybrids were ascertained by the presence of both parental genotypes at the LDH-A, ME-A, MDH-A and GPI loci. The maternal origin of the hybrid mtDNA was confirmed by digestion with DdeI, TaqI, HpaII of the COI region. No polymorphism was observed in the 16S rRNA region. The hybrids had gonadal development and maturity stages similar to the parental species up to fully mature oocytes and sperm. They spawned upon stimulation and produced viable offspring with high fertilization rates and successful development to the juvenile stage in back- and homologous hybrid crosses. [source]