In this study,
genetic samples from mothers and their offspring were collected from 22 litters
of wild copperhead snakes from Connecticut and 37 litters of wild cottonmouth
snakes from Georgia. After analyzing the DNA of these snakes, researches
discovered homozygous
maternal alleles across all loci in both species’ offspring. In other words, “the offspring were
solely the product of the mother, with no genetic contributions from the father”.
What was even more surprising to the researchers was the frequency - between
2.5% and 5% of offspring in these species may be a result of parthenogenesis.
Parthenogenesis
occurs during meiosis when sex cells are dividing. Because the sex cells only
contain half the genetic material necessary to create offspring, pairs of sex
cells in the snakes (and other species that undergo parthenogenesis) fuse
together. Embryos then form from the mother’s fused sex cells. These offspring,
however, are not clones of their mother because the sex cells that fused were
not “identical halves of her genome”.
Before
this study, scientists had only observed parthenogenesis in animals held in
captivity. This study was important because it was conducted on wild snakes,
revealing that parthenogenesis is in fact, not “a captive syndrome”. Even when
able to mate with a male, some within these species still reproduced via
parthenogenesis. Going forward, scientists are hoping to expand their research
to more species, such as water snakes in Oklahoma. Scientists are also curious
in following the offspring of virgin births to see how they survive and
reproduce.
Sources:
No comments:
Post a Comment