Differentiation of the rat seminiferous tubules between 13 and 19 days of age

Hagenäs, Lars; Plöen, L.; Ekwall, H.; Osman, D. I.; Ritzén, E. M.

doi:10.1111/j.1365-2605.1981.tb00709.x

Cited by 24 publications

(16 citation statements)

References 12 publications

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“…The temporal expression of ABP mRNA in the rat testis closely matches the volume density of Sertoli cells, which peaks at day 15 with a proportionally lower number in the adult testis, where the Sertoli cells are diluted by the increased number of germ cells. The late onset of GAD mRNA expression in the testis suggests that GAD mRNA is not expressed in Sertoli cells but rather in germ cells, more specifically, in round and condensing spermatids which appear in the testis at this time (2,15). In agreement with this, in situ hybridization revealed GAD mRNA-positive spermatocytes and round spermatids in the middle part of the seminiferous tubules with no labeling over interstitial tissues.…”

Section: Discussionsupporting

confidence: 68%

Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells.

Persson¹,

Pelto‐Huikko²,

Metsis³

et al. 1990

Mol. Cell. Biol.

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The gene encoding glutamic acid decarboxylase (GAD), the key enzyme in the synthesis of the inhibitory neurotransmitter y-aminobutyric acid, is shown to be expressed in the testis of several different species.Nucleotide sequence analysis of a cDNA clone isolated from the human testis confirmed the presence of GAD mRNA in the testis. The major GAD mRNA in the testis was 2.5 kilobases. Smaller amounts of a 3.7-kilobase mRNA with the same size as GAD mRNA in the brain was also detected in the testis. In situ hybridization using a GAD-specific probe revealed GAD mRNA expressing spermatocytes and spermatids located in the middle part of rat seminiferous tubules. Studies on the ontogeny of GAD mRNA expression showed low levels of GAD mRNA in testes of prepubertal rats, with increasing levels as sexual maturation is reached, compatible with GAD mRNA expression in germ cells. In agreement with this, fractionation of cells from the rat seminiferous epithelium followed by Northern (RNA) blot analysis showed the highest levels of GAD mRNA associated with spermatocytes and spermatids. Evidence for the presence of GAD protein in the rat testis was obtained from the demonstration of GAD-like immunoreactivity in seminiferous tubules, predominantly at a position where spermatids and spermatozoa are found. Furthermore, GAD-like immunoreactivity was seen in the midpiece of ejaculated human spermatozoa, the part that is responsible for generating energy for spermatozoan motility.Neurotransmitter-synthesizing enzymes are predominantly expressed in the nervous system, where their enzymatic products function in synaptic transmission. A similar restricted pattern of gene expression has also been inferred for neuropeptides, and a large amount of evidence suggests that these peptides also function in neurotransmission. However, in recent years, several neuropeptides have also been shown to be expressed in nonneuronal tissues, suggesting a broader function for these peptides than heretofore anticipated. Thus, oxytocin and vasopressin have been shown to be expressed in the thymus (12). Preprotachykinin A mRNA, the common precursor for substance P and neurokinin A, is also expressed in the thymus (A. Ericsson, V.

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Section: Discussionsupporting

confidence: 68%

Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells.

Persson¹,

Pelto‐Huikko²,

Metsis³

et al. 1990

Mol. Cell. Biol.

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“…The results extend our recent detection of CCK immunoreactivity in the seminiferous tubules of the mouse testis (29) and document a transient expression of CCK mRNA in male germ cells, with accumulation of CCK peptide in the acrosomal granule of spermatids and possibly also in spermatozoa. The maximal expression of CCK mRNA in testis of prepubertal rat coincides with the occurrence of increasing numbers of spermatocytes in the seminiferous tubules (30,31). Further evidence for this was obtained by in situ hybridization, which showed intense labeling over the basal part of the seminiferous tubules.…”

Section: Discussionmentioning

confidence: 72%

Transient expression of the cholecystokinin gene in male germ cells and accumulation of the peptide in the acrosomal granule: possible role of cholecystokinin in fertilization.

Persson

Rehfeld²,

Ericsson³

et al. 1989

Proc. Natl. Acad. Sci. U.S.A.

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Expression of the gene encoding the neurotransmitter/neuromodulator cholecystokinin (CCK) was demonstrated in testis ofseveral different species. Two tcular CCK mRNA transcripts of different sizes were detected, and studies on the ontogeny of CCK gene expression indicated that the gene was expressed in male germ ceils. In situ hybridization revealed CCK mRNA-expressing cells in the peripheral parts of the seminiferous tubules. Biochemical identification showed that the majority of prepro-CCK products in the testis represented pro-CCK. Immunofluorescence studies revealed CCK-like peptides primarily in spermatocytes and spermatids of mouse, rat, and monkey. Immuno electron microscopy of monkey testis demonstrated CCK immunoreactivity in the acrosomal granule of spermatids. Hence, an interesting possibility is that CCK peptides can be released during the acrosome reaction and thus may be of importance in the fertilization process.Cholecystokinin (CCK) was first purified by Jorpes and Mutt (1, 2) as a 33-amino acid peptide (CCK-33) from pig gut. Several different forms of CCK have been described in central and peripheral tissues (3-6). The brain contains CCK-8 and several CCK desoctapeptides but no detectable CCK-33. In the gut, however, intact CCK-33, CCK-39, and CCK-58 have been found together with the forms also seen in the brain (3-6). CCK-8 has been detected in many regions of the vertebrate nervous system (7-14) and fulfills several of the criteria of a neurotransmitter/neuromodulator (for review, see ref. 15), although the overall role of CCK in the brain is poorly understood.Molecular cloning of cDNAs for both pig and rat CCK mRNA has established that all identified CCK peptides are derived by proteolytic processing from a 114-or 115 (rat)-amino acid precursor that is identical in brain and gut (16,17). The various molecular forms of CCK in the brain and gut are therefore generated by tissue-specific posttranslational events. In accordance with this an '=0.8-kilobase (kb) CCK mRNA has been demonstrated in rat brain and gut (16,17).In this study the distribution of CCK mRNA and CCK peptides was examined in several tissues, including the male reproductive system. CCK immunoreactivity was detected in spermatogenic cells, and its occurrence in the acrosome of male germ cells indicates a possible role of CCK in the fertilization process.MATERIALS AND METHODS RNA Preparations and Blot Analysis. Total and poly(A)+ RNAs (18) were prepared from the indicated tissues, electrophoresed in 1% agarose gels containing 0.7% formaldehyde, and transferred to nitrocellulose filters (19,20). The filters were hybridized to a 540-base-pair rat CCK cDNA insert (16) labeled with [a-32P]dCTP by nick-translation to a specific activity of =5 x 108 cpm/,ug. Filters containing RNA prepared from rat tissues were washed at high stringency (0.1 x SSC/0.1% SDS, 540C; 1 x SSC is 150 mM NaCI/15 mM sodium citrate, pH 7.0), whereas filters with RNA prepared from other species were washed at reduced stringency (0.2 x SSC/0.1% SDS, 450C)....

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“…These cells develop without further division to give rise to the spermatozoa, which are carried out of the testis to mature in the epididymis and await ejaculation or loss in the urine [see 13,35,36]. The age at which the various cell types appear has been well defined in rodents [37][38][39][40], and there are some data for nonhuman primates [41,42]. In humans, some authors [43] state that primary spermatocytes are not present until puberty, while in another study [44], primary spermatocytes were present in a few tubules in some individuals from the age of 4 years onwards; even some spermatids were seen, but no spermatozoa, so the meiotic cells must have been degenerating.…”

Section: Germ Cellsmentioning

confidence: 99%

Postnatal Testicular Development, Cellular Organization and Paracrine Regulation

Setchell

Hertel²,

Söder³

2003

Endocrine Development

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Differentiation of the rat seminiferous tubules between 13 and 19 days of age

Cited by 24 publications

References 12 publications

Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells.

Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells.

Transient expression of the cholecystokinin gene in male germ cells and accumulation of the peptide in the acrosomal granule: possible role of cholecystokinin in fertilization.

Postnatal Testicular Development, Cellular Organization and Paracrine Regulation

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