Navigation Links
Bottom of the swimming league: Naked mole rat sperm

Naked mole rats (Heterocephalus glaber) live in a 'hive' society with one reproducing queen and between one and three reproducing males. The rest of the mole rats in the colony are workers either defending the burrow or finding food not an easy task when you are virtually blind and all the tunnels smell of mole rat. New research published in BioMed Central's open access journal BMC Evolutionary Biology shows that mole rat sperm has become simple and degenerate, probably due to 'orthogenic' (straight line) evolution.

Dubbed 'sabre-toothed sausages' these burrowing mammals have several weird attributes. They are unable to feel pain in their skin, or regulate their body temperature properly, and for such a small animal they live exceptionally long lives more than 20 years. They can move backwards as fast as forwards a neat trick when you live in tunnels, and, like ants, the mole rats recognise their colony by a group smell.

Researchers from South Africa examined the sperm of naked mole rats originating from Kenya. They used males from three different social strata: breeding males, subordinate workers, and 'disperser' males which, although they never consorted or bred with their queen, would attempt to mate with unrelated females.

There was no discernable difference in the sperm from any of the three groups of males, with only 1-15% of the sperm able to swim at all and only 1% of these active sperm being fast swimmers.

The sperm in all cases would be considered abnormal for any other mammal. The sperm head is irregular, often lobular, and the chromatin within the nucleus is dispersed. The neck is poorly developed and the sperm have the smallest mid-piece of any known mammal, with randomly arranged mitochondria. The most degenerate feature of naked mole rat sperm is the tail which is missing the fibrous covering thought to be essential for swimming through the female reproductive tract.

Prof Gerhard van der Horst from University of the Western Cape explained, "Once the queen has picked her consort(s) she keeps the other females and males subordinate by using physical aggression. It seems that the resultant lack of competition between breeding males for the colony queen contributed to an overall decrease in sperm 'fitness'. Surprisingly, despite the low motility and dismal features of their sperm, these naked mole-rat males are fertile and fathered a number of healthy offspring per litter. We are very excited about our results because this would be the first example of degenerate orthogenesis occurring at a cellular level."


Contact: Dr. Hilary Glover
BioMed Central

Related biology news :

1. Stevens hosts Green Building: The Bottom Line, April 8
2. LSU gets to the bottom of things -- in Antarctica
3. Move over predators: Plants can control the food chain too -- from the bottom up
4. Beauty from the bottom up
5. Project aims to fuse top-down, bottom-up approaches in systems biology
6. Biosensors reveal how single bacterium gets the message to split into a swimming and a stay-put cell
7. Swimming upstream: Molecular approaches to better understand male infertility
8. Swimming microorganisms stir things up, and the LHC takes over
9. Computational model of swimming fish could inspire design of robots or medical prosthetics
10. Penn research answers long-standing question about swimming in elastic liquids
11. Simple nerve cells regulate swimming depth of marine plankton
Post Your Comments:
Related Image:
Bottom of the swimming league: Naked mole rat sperm
(Date:5/16/2016)...   EyeLock LLC , a market leader of ... an IoT Center of Excellence in Austin, ... of embedded iris biometric applications. EyeLock,s iris ... security with unmatched biometric accuracy, making it the most ... EyeLock,s platform uses video technology to deliver a fast ...
(Date:4/28/2016)... First quarter 2016:   , Revenues amounted ... quarter of 2015 The gross margin was 49% (27) ... the operating margin was 40% (-13) Earnings per share ... operations was SEK 249.9 M (21.2) , Outlook   ... M. The operating margin for 2016 is estimated to ...
(Date:4/15/2016)... -- Research and Markets has announced the ...  report to their offering.  ,      ... gait biometrics market is expected to grow at ... Gait analysis generates multiple variables such ... compute factors that are not or cannot be ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Seattle, WA (PRWEB) , ... June 23, 2016 ... ... technology, announces the release of its second eBook, “Clinical Trials Patient Recruitment and ... patient recruitment and retention in this eBook by providing practical tips, tools, and ...
(Date:6/23/2016)... - FACIT has announced the creation of a ... Propellon Therapeutics Inc. ("Propellon" or "the Company"), to ... of first-in-class WDR5 inhibitors for the treatment of ... an exciting class of therapies, possessing the potential ... patients. Substantial advances have been achieved with the ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... Plate® YM (Yeast and Mold) microbial test has received AOAC Research Institute approval ... of microbial tests introduced last year,” stated Bob Salter, Vice President of Regulatory ...
(Date:6/23/2016)... 23, 2016   EpiBiome , a precision microbiome ... in debt financing from Silicon Valley Bank (SVB). The ... to advance its drug development efforts, as well as ... "SVB has been an incredible strategic partner to ... traditional bank would provide," said Dr. Aeron Tynes ...
Breaking Biology Technology: