Sperm quality and the morphology of cryopreserved testicular tissues recovered post-mortem from diverse wild species

This study compared the effects of slow and fast freezing of testicular tissue of wild animals collected at post-mortem on testicular structure and testicular sperm. The testes of seven animals that had died in captivity; three felids (jungle cat, lion and leopard), two cervids (rusa deer and fea’s muntjac) and two bovids (Sumatran serows) were cryopreserved using slow- and fast-freezing protocols. There were greater reductions in the integrity of the sperm membrane and DNA in tissues cryopreserved using slow freezing compared to fast freezing (membrane integrity reduced by 21.5 ± 12.4% vs. 13.0 ± 6.9%, P = 0.11 and DNA integrity reduced by 22.7 ± 16.3% vs. 6.6 ± 6.3%, P = 0.13). Histologically, there were similar degrees of detachment and shrinkage of the seminiferous tubules whereas, TUNEL assay revealed a tendency towards more apoptotic changes in the intra-tubular cells of tissues frozen using fast freezing compared to slow freezing (P = 0.09). In conclusion, fast freezing tended to cause less damage to testicular sperm but its protective effect on intra-tubular cells was likely compromised. This is the first report of gamete recovery in the wild and of the comparison in various wildlife species, between testicular tissues cryopreserved using different protocols.     

Distribution of estrogen receptor alpha and progesterone receptor, and leukocyte infiltration in the cervix of cyclic bitches and those with pyometra

The objectives were to localize estrogen receptor alpha (ERα) and progesterone receptor (PR), and enumerate leukocyte infiltration in cervical tissue of normal bitches during various stages of the estrous cycle (n = 35), as well as in those developing open (n = 22) or closed-cervix pyometra (n = 19). Each pyometra group was subdivided into anestrus and diestrus. Cervical tissues were collected after ovariohysterectomy. Receptor expressions were determined by immunohistochemistry and leukocyte infiltration was evaluated in histological sections stained with haematoxylin-eosin. The assessment was performed in two parts of cervical sections: the uterine part in four tissue layers (surface epithelium (SE), lamina propria (LP), glandular epithelium (GE), and tunica muscularis (M)), and the vaginal part in three layers (SE, LP and M). An immunohistochemical total score consisted of the addition of both the intensity and proportional scores. The ERα and PR scores differed between groups (P < 0.05) and between layers (P < 0.05), but were not significantly different between uterine and vaginal parts. The ERα score was lowest in the open-cervix pyometra bitches at anestrus and in closed-cervix pyometra bitches at diestrus. For all types of immune cells, there were no significant differences among stages of the estrous cycle in normal bitches, whereas neutrophils were lower in both sub-groups of closed-cervix versus open-cervix pyometra (P < 0.05). In conclusion, distributions of ERα and PR were similar along the longitudinal axis of the canine cervix. We inferred that cervical dilation in normal bitches and bitches with uterine pathology was likely controlled by different mechanisms. Receptor expressions were influenced by stage of the estrous cycle in normal bitches, whereas neutrophil infiltration in cervical tissue appeared to be involved in cervical dilation in bitches with pyometra, regardless of estrous stages.     

Expression levels of genes involved in metal homeostasis,physiological adaptation,and growth characteristics of rice (Oryza sativa L.) genotypes under Fe and/or Al toxicity

Acid sulphate soil contains high amounts of iron (Fe) and aluminum (Al), and their contamination has been reported as major problems, especially in rainfed and irrigated lowland paddy fields. Rice is sensitive to Fe and Al grown in acid soil (pH < 5.5), leading to growth inhibition and grain yield loss. The objective of this study was to evaluate Fe and/or Al uptake, translocation, physiological adaptation, metal toxicity, and growth inhibition in rice genotypes grown in acid soil. Fe and Al in the root tissues of all rice genotypes were enriched depending on the exogenous application of either Fe or Al in the soil solution, leading to root growth inhibition, especially in the KDML105 genotype. Expression level of OsYSL1 in KDML105 was increased in relation to metal uptake into root tissues, whereas OsVIT2 was downregulated, leading to Fe (50.3 mg g⁻¹ DW or 13.1 folds over the control) and Al (4.8 mg g⁻¹ DW or 2.2 folds over the control) translocation to leaf tissues. Consequently, leaf greenness (SPAD), net photosynthetic rate (P_n), stomatal conductance (g_s), and transpiration rate (E) in the leaf tissues of genotype KDML105 under Fe + Al toxicity significantly declined by 28.4%, 35.3%, 55.6%, and 51.6% over the control, respectively. In Azucena (AZU; Fe/Al tolerant), there was a rapid uptake of Fe and Al by OsYSL1 expression in the root tissues, but a limited secretion into vacuole organelles by OsVIT2, leading to a maintenance of low level of toxicity driven by an enhanced accumulation of glutathione together with downregulation of OsGR expression level. In addition, Fe and Al restrictions in the root tissues of genotype RD35 were evident; therefore, crop stress index (CSI) of Fe + Al–treated plants was the maximum, leading to an inhibition of g_s (53.6% over the control) and E (49.0% over the control). Consequently, free proline, total phenolic compounds, and ascorbic acid in the leaf tissues of rice under Fe + Al toxicity significantly increased by 3.2, 1.2, and 1.5 folds over the control, respectively, indicating their functions in non-enzymatic antioxidant defense. Moreover, physiological parameters including leaf temperature (T_leaf) increment, high level of CSI (>0.6), SPAD reduction, photon yield of PSII (Φ_PSII) diminution, P_n, g_s, and E inhibition in rice genotype IR64 (Fe/Al-sensitive) under Fe + Al treatment were clearly demonstrated as good indicators of metal-induced toxicity. Our results on Fe- and/or Al-tolerant screening to find out the candidate genotypes will contribute to present screening and breeding efforts, which in turn help increase rice production in the Fe/Al-contaminated acid soil under lowland conditions.

     

Steroid hormone receptors ERα and PR characterised by immunohistochemistry in the mare adrenal gland

Background  

Sex steroid hormone receptors have been identified in the adrenal gland of rat, sheep and rhesus monkey, indicating a direct effect of sex steroids on adrenal gland function.