New Zealand female-only stick insect produces 'rogue' male in UK

The specimen, which was discovered by an insect enthusiast in Cornwall, could mean the animal is ready to start having sex

Eleanor Ainge Roy in Dunedin

Tue 6 Feb 2018 01.08 GMTLast modified on Tue 6 Feb 2018 06.50 GMT

A species of New Zealand stick insect that was thought to produce only females has hatched a rogue male in the UK countryside – and scientists say the rare event could mean the animal is ready to start having sex.

Scientists at Massey University in New Zealand said they were “disbelieving” when colleagues in the UK reported they had found a male of the Acanthoxyla inermis stick insect, as the species has only ever been known to produce females.

“All Acanthoxyla species use parthenogenetics to reproduce, which means that the females lay viable eggs without the need for fertilisation by a male,” said Professor Morgan-Richards of the School of Agriculture and Environment at Massey University

“No males of any Acanthoxyla species have ever been recorded, until now.”

Continued 

All-female mutant crayfish that clone themselves are taking over rivers and lakes around world

Invasive crustaceans reproduce without mating, and have spread from Germany to countries as diverse as Madagascar and Japan

Josh Gabbatiss Science Correspondent 

A crayfish species that came into existence less than 25 years ago has spread around the world by cloning itself.

The entire global population of marbled crayfish has been traced to a single female held in a German aquarium, which was born with the ability to reproduce without having its eggs fertilised by males.

Every marbled crayfish is female, and every egg laid is an exact clone of its mother.

The ability to reproduce quickly and with such ease made the crustaceans popular in the aquarium trade, but when they found their way into the wild the crayfish got out of control.

“It was known that the crayfish can establish itself in the wild after releases from the aquarium,” said Dr Frank Lyko, a researcher at the German Cancer Research Centre who has sequenced the genome of the marbled crayfish to understand its abilities. “But the news was that it can spread so rapidly and massively.”

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No males needed: All-female salamanders regrow tails 36 percent faster

Speedy regeneration could aid survival

Date:May 2, 2016

Source:Ohio State University

The lady salamander that shuns male companionship may reap important benefits.

For instance, when a predator snaps off her tail.

New research from The Ohio State University compared an all-female population of mole salamanders to a related heterosexual species and found they grew their tails back 36 percent faster. The unisexual salamanders (part of theAmbystoma genus) contain DNA of up to five species and reproduce primarily by cloning themselves.

Salamanders' tails play a critical role in predator avoidance. As larvae, tails help them swim away. Once the animals are land-dwellers, the tails act as a distraction.

After accounting for weight and size differences -- the all-female salamanders are larger and have more tail to grow back -- the team concluded that the unisexual animals regenerated tail tissue at 1.5 times the rate of their heterosexual counterparts.

"I don't think we expected it to happen so fast," said Robert Denton, co-author of the study and a graduate student in Ohio State's Department of Evolution, Ecology and Organismal Biology.

The study appears in the Journal of Zoology.

Populations of unisexual mole salamanders have survived millions of years through cloning. Because they aren't mating with males (though they do mix things up by "borrowing" sperm left behind on leaves and twigs), their DNA stays relatively static.

And that might lead a salamander scientist to suspect the species would fizzle out. (Passing harmful genetic mutations to generation after generation could be bad.)

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'Odd Little Creature' Skips Sex and Eats DNA

The tiny, all-female bdelloid rotifers have endured the past 80 million years without sex. New research shows that gobbling up foreign DNA from other simple life-forms might be the asexual animal's secret to survival.

In the study, scientists discovered that up to 10 percent of the active genes in bdelloids comes from bacteria and other organisms like fungi and algae. The finding adds to "the weirdness of an already odd little creature," said Alan Tunnacliffe, a Cambridge professor and lead author of the study.

"We don't know how the gene transfer occurs, but it almost certainly involves ingesting DNA in organic debris, which their environments are full of," Tunnacliffe explained in a statement. "Bdelloids will eat anything smaller than their heads!"


Read on:  http://www.livescience.com/24856-odd-little-creature-skips-sex-and-eats-dna.html