The smooth - bounder shark ( Mustelus mustelus ) just proved that it can reproduce without sperm , produce multiple offspring with identical genes . It ’s the first time recurrent parthenogenesis has been reported for the coinage , and broadens our noesis of all the ways that exist in nature to cook up a baby solo .
Parthenogenesis is sometimes mention to as “ virgin birth ” because it involves grow offspring from an ball without needing any sperm . There was asuspected vitrine of parthenogenesisin a tank of distaff still - cad shark at an aquarium in Italy ( television below ) , and now a new paper has found genetical evidence that they can multiply without sperm .
It ’s thought to be what ’s known as facultative parthenogeny , describing an fauna that can reproduce sexually as well as asexually . The drivers for going alone can motley , but a plunge in the male population is thought to be one , which is why cases of virgin birth often arise ( and are most noticeable in ) intent environs .
This fresh inquiry took samples from captive sharks to examine their inherited markers , revealing that the juvenileM. mustelustested were birth through parthenogenesis . This was clean from the homozygosity seen at each hereditary marker , which is consistent with an embryo developing from an egg – no male require .
It ’s a version of parthenogenesis calledautomixiswhere the egg can merge with cells called gelid bodies , which are leftover from the egg production process . This bring forth offspring that are similar to the mother but not precise clones , and they ’re generally all female .
instead , parthenogenesis in plants can occur by apomixis , which involves reproductive cells duplicating their chromosomes via mitosis . In this showcase , offspring are genetically very to their parent .
The subject area also revealed that virgin birth can occur annually in liquid - dog shark , make it the first report of recurrent parthenogeny . It also excluded the possibility that long - full term sperm cell storage could explain where these baby were come from , showing just how gifted these female sharks are .
“ This field represents the first genetically verified example of parthenogenesis inMustelus mustelusfrom 2020 forwards , ” concluded the discipline generator . “ These occurrences look to recur annually , alternating between two adult female shark , a phenomenon cover previously in the oviparous speciesStegostoma tigrinumas a facultative reception in the absence of a checkmate . ”
Smooth - hound shark now join a host of other critters who have evidence that when the sperm cell counting gets low , females can keep the population go away all on their unity . To date , we ’ve also seen parthenogeny amongCalifornia condor , Brazilian boas , zebra sharks , anaconda , andcrocodiles – a finding that ’s in particular supercilium - breeding and beg the motion : could dinosaur reproduce asexually ? Bring on the archosaurian reptile clones .
The bailiwick is published inScientific Reports .
