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Spermatozoa were present in the cauda epididymidis of male Rickett's big-footed bat, Myotis ricketti, from late September to early April but absent from the testes from mid November until late August. Males thus store spermatozoa in the cauda epididymidis for 4.5–6.5 months of the year. Assessments of sperm motility, movement pattern and computer-assisted sperm analysis (CASA) were carried out on spermatozoa which had been stored for over 3.5 months in the cauda epididymidis. The motility of sperm stored for the same period of time and taken from a male which died over 9 h before assessment was 86%. Four kinds of culture media were screened for their suitability for future studies of sperm motility, and a low calcium minimal capacitation medium and a hamster fertilization medium were selected. Serum testosterone (T) concentration increased dramatically in September and began to fall in October, before returning to baseline for the remainder of winter. These results indicate that high levels of T are required for spermatogenesis and spermiogenesis but not for sperm storage.
Boar seminal vesicle protein tyrosine acid phosphatase (PTAP) and human prostatic acid phosphatase (PAP) show high affinity for protein phosphotyrosine residues. The physico-chemical and kinetic properties of the boar and human enzymes are different. The main objective of this study was to establish the nucleotide sequence of cDNA encoding boar PTAP and compare it with that of human PAP cDNA. Also, the amino-acid sequence of boar PTAP was compared with the sequence of human PAP. PTAP was isolated from boar seminal vesicle fluid and sequenced. cDNA to boar seminal vesicle RNA was synthesized, amplified by PCR, cloned in E. coli and sequenced. The obtained N-terminal amino-acid sequence of boar PTAP showed 92% identity with the N-terminal amino-acid sequence of human PAP. The determined sequence of a 354 bp nucleotide fragment (GenBank accession number: GQ184596) showed 90% identity with the corresponding sequence of human PAP. On the basis of this sequence a 118 amino acid fragment of boar PTAP was predicted. This fragment showed 89% identity with the corresponding fragment of human PAP and had a similar hydropathy profile. The compared sequences differ in terms of their isoelectric points and amino-acid composition. This may explain the differences in substrate specificity and inhibitor resistance of boar PTAP and human PAP.
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