Effect of age and season on the testicular sperm reserve and testosterone profile in camel (camelus dromedarius)

Abstract The present investigation aimed to determine the effects of age and seasons of the year on the testicular sperm reserve and serum testosterone concentration in dromedary camels. Testes were collected from a local slaughterhouse during a period of one year (breeding and non-breeding seasons) from two age groups (GI: 4-6 yr and GII: 8-10 yr). Testicular sperm reserve was determined during the breeding (December-May) and non-breeding (June-November) seasons. Blood samples were collected for determination of serum testosterone concentration (ng/ml). There was highly significant difference (P < 0.01) in the testicular sperm reserve between breeding (13.58 x 10 9 ) and non-breeding (9.90 x 10 9 ) seasons. The serum testosterone concentration (ng/ml) was significantly increased during the breeding season (10.94 ng/ml) compared with that of the non-breeding season (4.43 ng/ml). Testicular sperm reserve (14.34 in GII vs. 9.13 in GI) and serum testosterone concentration (10.43 vs. 4.94 ng/ml) were significantly (P < 0.01) increased by age. It could be concluded that the age of the animal and season of the year have significant effects on the testicular sperm reserve and serum testosterone concentration in dromedary camels

Embryonic genome activation events in buffalo (Bubalus bubalis) preimplantation embryos

Embryonic genome activation (EGA) is the first major step towards successful initiation of preimplantation development, which culminates in the formation of implantation-competent embryos. EGA occurs at species-specific embryonic cell stages. In the present work, EGA was identified for buffalo embryos by studying the development rate of embryos in normal as well as imposed transcription block conditions, analyzing bromo-uridine triphosphate (BrUTP) incorporation rates as evidence of de novo transcription initiation, and studying the expression status of eukaryotic translation initiation factor 1A (eIF1A), U2 auxiliary splicing factor (U2AF), and polyadenylate polymerase (PAP) genes at different embryonic cell stages. Under normal, in vitro fertilization and culture conditions, about 26% and 17% of oocytes could reach morula and blastocyst stages, respectively, but no embryos could progress beyond 8-cell stages in presence of a-amanitin. Culturing embryos in the presence of BrUTP revealed a marked increase in its incorporation between 4- and 8-cell stages. All genes studied displayed an abrupt increase in expression between 4- and 8-cell stages; PAP expression was upregulated earlier from 2- to 4-cell stages. About 65% of PAP transcripts from the 4-cell stage and more than 70% of eIF1A, U2AF, and PAP transcripts at 8-cell stage embryos were found to be synthesized de novo. Together, these data suggest that a minor EGA in buffalo embryos happens from 2- to 4-cell stages, while the major EGA takes place from 4- to 8-cell stage transition. Mol. Reprod. Dev. 79: 321328, 2012. (C) 2012 Wiley Periodicals, Inc