Novel transcripts of carbonic anhydrase II in mouse and human testis

Abstract

Intracellular and extracellular sources of bicarbonate are essential for sperm motility, sperm binding to the zona pellucida and the acrosome reaction. Carbonic anhydrase II, catalysing the synthesis of bicarbonate within spermatozoa, must play a significant role in these mechanisms. We report here the expression of carbonic anhydrase II during mouse spermatogenesis and the primary structure of testicular transcripts coding for carbonic anhydrase II isolated from adult mouse and human testes. The mouse carbonic anhydrase II (Car2) mRNA displays a 5Ј untranslated region (UTR) larger than the corresponding somatic sequence. The additional 5Ј sequence contains the 'TATA box' used in somatic tissues and other promoter sequences, suggesting the use of testis-specific promoters further upstream with read-through of downstream promoters. The 3ЈUTR of the Car2 mRNA is shorter in mature testicular cells than in somatic cells. Polysomal gradient analysis of carbonic anhydrase II transcripts isolated from adult mouse testis and kidney revealed different translation potential: most of the testicular transcripts were present in the non-polysomal fractions, whereas a considerable fraction of kidney transcripts were polysome-associated. These results suggest that specific transcriptional and post-transcriptional mechanisms regulate the expression of carbonic anhydrase II during mammalian spermatogenesis.

Expression of lactate dehydrogenases A and B during chicken spermatogenesis: Characterization of testis specific transcripts

“…Formation of these potential structures could hinder a premature translation of the transcripts during spermatogenesis. Previously we have observed the same phenomenon in several genes expressed during avian and mammalian spermatogenesis [Mezquita et al, 1999].…”

“…7, lane 2). A similar distribution of the testis specific LDH-C in mammals has been reported [Fujimoto et al, 1988;Alcivar et al, 1991;Mezquita et al, 1999]. We have used the distribution of the 6kb QKI mRNA in the same sample as a control.…”

Specific expression of pfkfb4 gene in spermatogonia germ cells and analysis of its 5′‐flanking region

“…The human pfkfb4 transciption start site, refered as +1, was located at position À25 from the translation start codon. However, we could not discard the existence of other potential initiation sites as has been described in other testis specific genes [22,23]. The minimal promoter unit of human pfkfb4 gene comprises the region between nucleotides À141 and +1.…”

“…This peptide comprises a unique region of the tPFK-2 (amino acids [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]) that differs significantly from the corresponding sequence of the other PFK-2 isozymes. This antibody does not recognize the liver or ubiquitous isoforms that were identified by an antibody against liver PFK-2 (L-PFK-2) (Santa Cruz, California, USA) and against ubiquitous PFK-2 (uPFK-2) [13].…”

“…To elucidate whether pfkfb4 and pfkfb3 gene products are present specifically in different cells, we generated a specific antibody against tPFK-2 that comprises a unique region of the tPFK-2 (amino acids [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]) that differs notably from the corresponding sequence of other PFK-2 isozymes. As shown in Fig.…”