Naturally monozygotic quadruplets in a Braford cow confirmed by DNA analysis: a case report

ROGBERG?MUÑOZ, ANDRÉS; CASTILLO, NADIA S.; ZAPPA, MARÍA E.; CRESPI, JULIÁN A.; VILLEGAS CASTAGNASSO, EGLE E.; GÓMEZ, PAULA M.; KIENAST, MARIANA*; VILLEGAS- CASTAGNASSO, EGLE; PERAL GARCÍA, PILAR.;; GIOVAMBATTISTA, GUILLERMO

REPRODUCTION IN DOMESTIC ANIMALS (1990)

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020

0936-6768

AbstractCattle are a monotocous species, despite naturally conceived multiple births aresometimes observed. Although the number of twins has consistently increased, triplet and quadruplet pregnancies represent 0.015% and 0.004% of the total births,respectively. Multiple births are the result of multiple ovulation and/or the spontaneous cleavage of one fertilized oocyte, which is known as monozygotic (MZ) twinning. In cattle, approximately 5% to 14% of all twin births are MZ, and births withmore than two MZ calves are extremely rare. Monozygotic animals are geneticallyidentical, and those derived from two or more zygotes are genetically different.Furthermore, the presence of placental vascular anastomosis can result in foetal chimerism. Notwithstanding, animals born as single calves can be chimeras when oneof the foetal twins dies undetected in utero. Here, we used DNA testing to study thezygotic condition of an unusual female quadruplet born from a Braford cow bred ina multi-sire natural mating system without hormone stimulation. Two tissues withdifferent embryological origin were sampled to test zygosity and possible chimerism.The results showed an identical genotype, confirming they all originated in an MZpregnancy and suggesting the lack of chimerism in all animals. The use of MZ twins inbreeding and selection systems provides an alternative to the conventional progenytesting. Some works have suggested a genetic background of MZ twins in humans.This female and her daughters could be the founders of a lineage to study the possible inheritance of MZ multiple births in cattle.