Effect of maternal age and parity on preimplantation embryo development and transport in the golden hamster (Mesocricetus auratus)

Abstract

SummaryPreimplantation embryo development was studied in the golden hamster (Mesocricetus auratus). Three groups of regularly cycling female hamsters were used: (I) 30 nulliparous young female (NYF) hamsters; (II) 24 nulliparous adult female (NAF) hamsters and (III) 30 multiparous adult female (MAF) hamsters. Female hamsters were mated with male hamsters of proven fertility. Only 15 min were allowed for mating. The moment of ejaculation was registered. Female hamsters were killed from 60 to 69 h after coitus. Corpora lutea were counted in both ovarian surfaces. Oviducts and uterine horns were flushed separately and embryo number, stage of development and distribution were recorded. Adult female hamsters, nulliparous and multiparous, had significant higher ovulation rates than NYF, but their reproductive efficiency was significantly lower. Preimplantation embryo development and transport were highly synchronous in NYF, but not in adults. Morulae were observed in NYF as early as 62-63 h after coitus. In adult female hamsters, significant numbers of morulae were found until 66-67 h. On the contrary, in NYF four-cell embryos were detected only until 60-61 h, while four-cell embryos were found until 64-65 h in NAF, and until 66-67 h in MAF. Embryo transport from the oviduct to the uterus is practically completed at 62-63 h after coitus in NYF, while it is evidently retarded in adult animals. In NYF all eight-cell embryos reached the uterus by 62 h after coitus. In adult female hamsters, both nulliparous and multiparous, a considerable number of eight-cell embryos fail to migrate into the uterus even at 67 h after coitus.

The hamster as a model for embryo implantation: Insights into a multifaceted process

“…h post coitus [1], the late morula or early blastocyst stage enters the uterus at about 72 post coitus in mice [2] Although blastocyst formation (cavitation) occurs within the uterus in most species, blastocyst formation in hamsters occurs after the 4 th cleavage (16-cell stage) compared to 5 th cleavage (32-cell stage) in mice.…”

Efecto del uso de medio secuencial humano en la producción de blastocistos de hembra ovis canadensis mexicana por clonación manual

“…Esto apunta a que en el medio simple ocurrió una asincronía y retraso del desarrollo embrionario más marcado al compararlo con el medio secuencial humano. Navarro et al, (2000) y Trejo et al, (2005), observaron una marcada asincronía y retraso del desarrollo in vivo de embriones en etapas de 2 blastómeros a mórula en hámster adulta, relacionado a un posible bloqueo del desarrollo embrionario correspondiente con el transporte del embrión del oviducto al útero y explican que esto puede deberse a la edad y paridad de la hembra, más que a factores de autoregulación del desarrollo y transporte del embrión. En el caso del presente trabajo, se utilizaron ovocitos de ovejas domésticas adultas como citoplastos y fibroblastos de oveja cimarrona también adulta como carioplastos, lo cual pudo influir en el bloqueo del desarrollo embrionario.…”

Presence and distribution of E-cadherin in the 4-cell golden hamster embryo. Effect of maternal age and parity

“…All utilized animals were born in our animal facilities and kept at 25 °C under controlled conditions, with a light: dark cycle of 14: 10 h and food and water ad libitum . Normally cycling hamster females (Trejo et al ., 2005), were divided into three experimental groups: (1) nulliparous young (2-month-old) females (NYF) weighing 128 ± 15 g; (2) nulliparous adult (8-month-old) females (NAF) weighing 168 ± 18 g; and (3) multiparous (four pregnancies), adult (7–8-month-old) females (MAF).…”

“…Universidad Autonoma Metropolitana. 1 have recently shown (Trejo et al, 2005) that adult (8-month-old) nulliparous and multiparous females show significant asynchrony and retard on early embryo development (from two blastomeres to morula stages) when compared with nulliparous young (2-month-old) females.…”