Testis Morphology (testis + morphology)

Distribution by Scientific Domains


Selected Abstracts


Reproductive morphology of Brittanichthys axelrodi (Teleostei: Characidae), a miniature inseminating fish from South America

JOURNAL OF MORPHOLOGY, Issue 1 2007
Robert Javonillo
Abstract Light and electron microscopy were used to investigate the morphology of reproductive characters in a characid fish, Brittanichthys axelrodi. Spermatozoa were found in ovaries of females, thereby confirming insemination in this species. Bony hooks can be found on the fourth unbranched ray and branched rays 1,4 of the anal fin and the unique sigmoidally-curved ray of the caudal fin in mature males. Testes have three distinct regions: an anterior spermatogenic region, an aspermatogenic middle region lined with a simple squamous epithelium and used for storage of mature spermatozoa, and a posterior region of coiled chambers lined with a high simple cuboidal epithelium. The most posterior region appears to be instrumental in the formation and storage of spermatozeugmata, unencapsulated sperm packets. Thus far, this tripartite testis morphology is unique among characids. The mature spermatozoon has an elongate nucleus (,5 ,m in length). A striated rootlet originates at the anterior end of the distal centriole and continues to the anterior tip of the cell. The striated rootlet wraps around the entire ventral area of the anterior part of the nucleus and appears to continue around the anterior tip of the nucleus and down the dorsal side as electron-dense material. Several large, spherical mitochondria (,0.6 ,m in diameter) with lamellar cristae overlap the posterior end of the nucleus and continue beyond together with the cytoplasmic collar that contains the flagellum which lacks axonemal fins. Each spermatozeugma is lanceolate in shape when sectioned mid-sagitally, with the core staining positively for mucopolysaccharides. In both sexes, the gonopore opens posterior to the anus, with the urinary pore having a separate opening posterior to the gonopore. Bands of skeletal muscle were found in the area of the male gonopore. These morphological features are likely linked to the reproductive mode of insemination, a trait that is so far as known, relatively rare among teleost fishes, but is proving increasingly frequent among certain groups of characid fishes. J. Morphol, 2006. © 2006 Wiley-Liss, Inc. [source]


Expression of FGF2 and TGF, and testis morphology during testicular hypertrophy subsequent to hemicastration in the neonatal boar

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 6 2008
R. Wells
Abstract The objective was to ascertain fibroblast growth factor-2 (FGF2), epidermal growth factor (EGF), and transforming growth factor-, (TGF,) mRNA expression and testis morphology during accelerated testicular growth after hemicastration in the neonatal boar. On Day 10 after birth (Day 0), boars were assigned to control (n,=,28), no treatment; hemicastrated (n,=,28), left testis removed. The right testis in both groups (n,=,7) was removed on Days 5, 10, 15, and 20. Expression of mRNA for FGF2, EGF, and TGF, was determined by qRT-PCR using TaqMan®. Testicular morphology was determined on Day 15. On Day 10, hemicastrated boars had a greater (P,=,0.01) testis weight (6.2,±,0.8 g; mean,±,SEM) than controls (4.3,±,0.4 g) and on Day 15 testis weight in hemicastrated boars (8.8,±,0.8 g) was twice (P,<,0.01) that of control boars (4.2,±,0.3 g). Seminiferous tubule volume was approximately doubled in hemicastrated boars (P,<,0.01) and was associated with an increase (P,<,0.01) in Sertoli cell number. Interstitial compartment volume was greater (P,<,0.01) in hemicastrated boars. Leydig cell numbers were similar (P,=,0.14) but volume was greater (P,<,0.01) for hemicastrates. There were no differences (P,> 0.05) between control and hemicastrated boars in TGF, or FGF2 expression on Day 5 or Day 10, and EGF was not detected. It was concluded that upregulation of TGF, or FGF2 expression is not a pre-requisite for enhanced testicular growth and increased Sertoli cell proliferation that occurs subsequent to hemicastration in the neonatal boar. Mol. Reprod. Dev. 75: 961,966, 2008. © 2008 Wiley-Liss, Inc. [source]


Mice deficient for RNA-binding protein brunol1 show reduction of spermatogenesis but are fertile

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 11 2007
Arvind Dev
Abstract RNA-binding proteins are involved in post-transcriptional processes like mRNA stabilization, alternative splicing, and transport. Brunol1 is a novel mouse gene related to elav/Bruno family of genes encoding for RNA-binding proteins. We report here the expression and functional analysis of murine Brunol1. Expression analysis of Brunol1 during embryogenesis by RT-PCR showed that Brunol1 expression starts at 9.5 dpc and continues to the later stages of embryonic development. In adult mice, the Brunol1 expression is restricted to brain and testis. We also analyzed the Brunol1 expression in testes of different mutants with spermatogenesis defects: W/WV, Tfm/y, Leyl,/,, olt/olt, and qk/qk. Brunol1 transcript was detectable in Leyl,/,, olt/olt, and qk/qk mutant but not in W/WV and Tfm/y mutants. We also showed by transfection of a fusion protein of green fluorescent protein and Brunol1 protein into NIH3T3 cells, that Brunol1 is localized in cytoplasm and nucleus. In order to elucidate the function of the Brunol1 protein in spermatogenesis, we disrupted the Brunol1 locus in mouse by homologous recombination, which resulted in a complete loss of the Brunol1 transcript. Male and female Brunol1+/, and Brunol1,/, mice from genetic backgrounds C57BL/6J,×,129/Sv hybrid and 129X1/SvJ when inbred exhibited normal phenotype and are fertile, although the number and motility of sperms are significantly reduced. An intensive phenotypic analysis showed no gross abnormalities in testis morphology. Collectively our results demonstrate that Brunol1 might be nonessential protein for mouse embryonic development and spermatogenesis. Mol. Reprod. Dev. 74: 1456,1464, 2007. © 2007 Wiley-Liss, Inc. [source]


Calgizarrin like gene (Cal) deficient mice undergo normal spermatogenesis

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2003
Ashraf U. Mannan
Abstract The murine calgizzarin like gene (Cal) encodes for a calcium binding protein, which belongs to the S100 family of EF-hand proteins. It is specifically expressed in Sertoli cells in the testis and its expression is down-regulated by unknown factor(s) from spermatocytes/spermatids. In this paper, we show by transfection of a fusion protein of green fluorescent protein and Cal protein into NIH3T3 cells, that the expression of Cal is restricted only in the cytoplasm of the cell. A differentially regulated cytoplasmic expression of the Cal in Sertoli cells during mouse development suggests that Cal might play an important role during spermatogenesis. In order to elucidate the function of the Cal protein in the spermatogenesis, we disrupted the Cal locus in mouse by homologous recombination. In our knockout mouse, we deleted exon 2 and exon 3 of the Cal gene and replaced them with a neomycin cassette, which resulted in a complete loss of the Cal transcript. Male and female Cal4+/, and Cal4,/, mice from genetic backgrounds C57BL/6J,× 129X1/SvJ hybrid and 129X1/SvJ inbred exhibited normal phenotype and were fertile. An intensive phenotypic analysis showed no gross abnormalities in testis morphology. The lack of the Cal protein also does not affect the parameters of sperm, as they are able to fertilize the oocytes in a competent manner, which is comparable to wild-type sperm. Collectively our results demonstrate that Cal is a nonessential protein and it does not play an important role in mouse spermatogenesis or in process of fertilization. Mol. Reprod. Dev. 66: 431,438, 2003. © 2003 Wiley-Liss, Inc. [source]