Role of genetic and physiological interrelationships of mother-offspring in establishing the viability and fertility of mammals. I. the embryonic development of mice with interstrain transfers of blastocysts
Evsikov, V.I.; Morozova, L.M.
Genetika 13(5): 826-839
1977
ISSN/ISBN: 0016-6758 PMID: 611043 Document Number: 110515
The weight of embryos and their placentas obtained by reciprocal 3.5 day blastocyst transfer between mouse females of the BALB/c and C57Bl/6J strains was analyzed on the 16th gestation day. Placental weight is determined by the genotype of the embryo and is not affected by its antigenic dissimilarities with the mother. The weight of allogenic embryos BALB (developed in C57Bl females) slightly exceeded the weight of syngeneic embryos of the same strain (developed in BALB females). The weight of allogenic B57Bl embryos in females with a different number of fetuses in the uterus exceeded by 32-36% the weight of syngeneic BALB embryos and by 10-54% the weight of syngeneic C57Bl embryos. The most significant differences in the weight of allogenic and syngeneic embryos were observed in females with a small number of embryos. Analysis of chromosome aberrations in somatic cells of syngeneic and allogenic embryos and their mothers did not confirm the suggestion about possible influence of mother-fetus antigenic dissimilarities on chromosome apparatus damages. Changes in the weight of BALB embryos, developed in C57Bl females, and C57Bl embryos, developed in BALB females, in comparison with the weight of syngeneic embryos are mainly the same as in reciprocal hybrid embryos. The role of mother-fetus histoincompatibility in establishment of embryonic viability is discussed. Increased weight and viability observed in many hybrid embryos are not due to heterozygosity per se, but originate from the more significant antigenic dissimilarity between mother and offspring. Inbred depression in mammals may be escaped by interstrain and interbreed transfer of early-stage embryos.