BackgroundIn order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically activated ovine oocytes and sperm selected by swim up (SU) or swim up + zona pellucida (SU + ZP) binding.ResultsExperiment 1, 4–20 replicates with total 821 in vitro matured oocytes were chemically activated with ethanol, calcium ionophore or ionomycin, to determine oocyte activation (precense of one PN). Treatments showed similar results (54, 47, 42 %, respectively) but statistically differents (P < 0.05) than mechanical activated oocytes in sham, ICSI and sham injection (13, 25, 32 %, respectively) (10–17 replicates; n = 429).Experiment 2: Twelve ejaculates and 28 straws of semen were used (11–19 replicates). Sperm were selected by SU in BSA-TCM 199-H medium. A total of 2,294 fresh sperm and 2,760 from frozen-thawed semen were analyzed after SU or SU + ZP binding. Fresh sperm selected by SU showed acrosome reaction (AR) of 59 %, the sperm selected by SU + ZP binding increased AR to 91 %. In comparison, the AR of frozen-thawed sperm using SU or SU + ZP binding was 77 and 86 %, respectively (P < 0.05).Experiment 3: fertilization in 200 mechanical activativated oocytes (17 replicates) was 4 %, but fertilization increased in ethanol activated oocytes after ICSI (12-28 %) (5–6 replicates). When fresh sperm only selected by SU were injected to 123 oocytes, a fertilization rate (28 %) was achieved; in sperm selected by SU + ZP was 25 % (73 oocytes). In comparison, in frozen-thawed sperm selected by SU, fertilization was 13 % (70 oocytes), whereas sperm from SU + ZP binding displayed 12 % (51 oocytes) (P > 0.05).ConclusionsChemical activation induces higher ovine oocyte activation than mechanical activation. Ethanol slightly displays higher oocyte activation than calcium ionophore and ionomicine. Sperm selection with SU + ZP increased AR/A and AR/D rates in comparison with SU in fresh and frozen-thawed sperm. According to this, in terms of fertilization rates, chemical activation after ICSI increased oocyte PN formation compared to mechanical activation. Also, fresh sperm treated with SU and SU + ZP were significantly different than frozen-thawed sperm, but between sperm treatments no significant differences were obtained.

Abstract. The presence of trypanosomatids in the reproductive systems of different mammals (causing genital lesions in the acute stage of the disease) may predispose the animals to low semen quality. However, there are no studies examining the alterations in the sperm morphological features in the chronic stage of Trypanosoma cruzi infection. Knowledge of these aspects is important to understand the other ways of transmission of the Chagas disease. Progressive motility, mass motility, concentration, and sperm morphology of 84 ejaculates of dogs that were chronically infected with T. cruzi were evaluated. Most of the findings were consistent with the reference values and with those obtained from healthy control dogs. The scrotal circumference was not correlated with spermatozoa concentration in the infected animals. In conclusion, the T. cruzi Ninoa (MHOM/MX/1994/Ninoa) strain does not cause significant alterations in the semen quality of dogs experiencing chronic Chagas disease (at concentrations of 5

. (2017). Efecto del uso de medio secuencial humano en la producción de blastocistos de hembra Ovis canadensis mexicana por clonación manual interespecies. Acta Zoológica Mexicana (n.s.), 33(2), 328-338. RESUMEN.Efecto del uso de medio secuencial humano en la producción de blastocistos de hembra Ovis canadensis mexicana por clonación manual interespecies. Desde el evidente problema del peligro de extinción que enfrenta un número significativo de especies silvestres a nivel mundial, se han aplicado biotecnologías encaminadas a promover su conservación y reproducción. Tal es el caso de la transferencia nuclear de células somáticas (TNCS) interespecies que ha sido aplicada y ha producido exitosamente embriones y crías nacidas vivas en algunas de estas especies. Sin embargo, la TNCS interespecies aún debe lidiar con otros problemas como la baja tasa de producción de embriones y de supervivencia de las crías nacidas (3-6%). Problemas que, entre otros, involucran la alta incidencia de fragmentación embrionaria. Los estudios son ahora dirigidos a resolver estos obstáculos, determinando el efecto de diferentes medios o suplementos utilizados en la producción in vitro de embriones. El objetivo de este estudio fue aplicar una variante de la TNCS interespecies (Clonación Manual-HMC) para la producción de embriones, determinando el efecto del uso de medios secuenciales humanos, en el borrego salvaje mexicano ABSTRACT. Effect of sequential human medium use in the production of blastocysts of female Ovis canadensis mexicana by interspecies handmade cloning. Faced to the notable problem that a significant number of world wild species are endangered, some biotechnologies such as the interspecific somatic cell nuclear transfer (SCNT), have been applied to raise their reproduction and conservation. This technology has been successfully applied by producing embryos and live offspring in some of these species. However, the interspecific SCNT still has to solve problems such as the low embryo production and offspring survival rates (3-6%). These problems, among others, involve a high incidence of embryo fragmentation and in order to solve them, most studies are now aimed to determine the effect of different culture media or supplements used for in vitro embryo production. Therefore, the aim of the present study was to use a variant of the interspecific SCNT technique (Handmade cloning-HMC) for embryo production, determining the effect of human sequential media in the endangered Mexican wild sheep O. c. mexicana. Results indicate that the embryo production increased when using human sequential media, allowing EFECTO DEL USO DE MEDIO SECUENCIAL HUMANO EN LA PRODUCCIÓN DE BLASTOCISTOS DE HEMBRA OVIS CANADENSIS MEXICANA