Navigation Links
The coelacanth leads a monogamous life
Date:9/19/2013

Scientists have successfully analysed the genetic make-up of the offspring of pregnant coelacanth females for the first time. They found that the likelihood that the offspring is fathered by one single individual is very high unlike with many other fish species. Dr Kathrin Lampert from the Ruhr-Universitt Bochum and Prof Dr Manfred Schartl from the University of Wrzburg, together with their colleagues, report about their findings in the journal "Nature Communications".

Analysis of the microsatellite DNA

The pregnant coelacanth females studied by the researchers were about to give birth to their offspring. One female that had accidentally ended up in a trawl net by the Mozambique coast was carrying 26 embryos, another one caught unintentionally by fishermen in Zanzibar waters was carrying 23. When comparing 14 characteristic spots in the genetic make-up of the females and of their offspring with each other, the researchers found numerous overlaps. They deployed a method that is also utilised for conducting paternity tests in humans, namely microsatellite analysis. Microsatellites are short DNA sequences, consisting of only a few units that, typically, may recur up to 50 times. They do not usually carry any genetic information, but they are passed down from both parents. "As we know the mother's genotype, we are able to demonstrate by means of the microsatellite analysis that coelacanth offspring have one single father," says Manfred Schartl. Consequently, coelacanth females must be monogamous at least for a certain period of time. The team also reconstructed the "hypothetical genotype", i.e. the hypothetical genetic make-up of both fathers.

Coelacanths do not take advantage of multiple mating

It is not clear why the females mate with one single male each. Mating with several males increases the chance of successful fertilisation, results in a higher genetic variability in the offspring and ensures that the best genes are passed on. It is possible that the advantages of multiple mating do not outweigh the costs for the female: increased energy input when searching for new males, danger of falling prey to predators, and an increased risk of infection.

No mating with relatives

The researchers discovered another interesting detail in the coelacanth's genetic make-up: father and mother of the offspring were not more closely related than the majority of random couples in a coelacanth population. This could mean that the females avoid mating with close relatives. Or that other features are more relevant in the choice for a suitable mate, for example size and frame or resistance against parasites.

Three years of pregnancy

In many fish species, fertilisation takes place outside the body. The females lay their eggs in a quiet spot in their aquatic environment; subsequently, the males it can be several add their semen. The offspring grow up in the water without their parents' protection whereas the coelacanth gives birth to fully developed young. Scientists estimate that the "pregnancy" takes about three years.

Coelacanths were thought to be extinct

Until December 23, 1938, scientists had been convinced that coelacanths were extinct. Only a few fossilised prints gave evidence that those animals had existed more than 300 million years ago. Then, fishermen by the South-African coast discovered a greyish blue fish with a length of some 1.50 m and a weight of some 52 kg in their trawl net: the first specimen of a living coelacanth. Today, the existence of some 300 specimen has been proved. It is very difficult to get hold of tissue samples of a complete litter of a pregnant coelacanth female. This was made possible by the co-authors of "GEOMAR" in Kiel and Tutzing who have been researching the coelacanths' habits and occurrence for many years.


'/>"/>

Contact: Dr. Kathrin Lampert
kathrin.lampert@rub.de
Ruhr-University Bochum
Source:Eurekalert

Related medicine news :

1. Epilepsy Leads to More Brain Abnormalities Over Time
2. How a cancer drug leads to diabetes
3. Georgetown physician leads national resveratrol study for Alzheimers disease
4. Study finds Massachusetts health reform leads to increased inpatient surgical procedures
5. Rutgers leads effort to replicate care management programs in 4 U.S. cities
6. Fun in the Kitchen and Eating 300 Calorie Meals Leads to Weight Loss for Fat Guy
7. AIUM and AUA guideline development leads to practice accreditation for urologic ultrasound
8. A Void In The Independent Pharmacy Industry Leads to Independent Rx Consulting, Powered by OurHelix
9. Protein build-up leads to neurons misfiring
10. Expanding Medicaid to low-income adults leads to improved health, fewer deaths
11. Stress during pregnancy leads to abdominal obesity in mice offspring
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/24/2017)... ... 2017 , ... “End Time GPS”: a dauntless and enlightened study of ... GPS” is the creation of published author, Wesley Gerboth, a World War II veteran, ... space-vehicle projects. Now, at age ninety-one, he shares the Wisdom God bestowed upon him ...
(Date:3/24/2017)... ... March 24, 2017 , ... “The Adventures of Joey, The Dog Who ... who lives his life to the fullest, as God intended. “The Adventures of Joey, ... a mother and grandmother pursuing her passion for writing, especially about truth and human ...
(Date:3/23/2017)... ... March 23, 2017 , ... The physicians of KSF Orthopaedic ... greater Houston Area. The new location is located at 2255 E. Mossy Oaks Rd., ... Village. This newest location will provide patients living in the north Houston area (The ...
(Date:3/23/2017)... Montclair, NJ (PRWEB) , ... March 23, 2017 ... ... the Renaissance Oklahoma City Convention Center at 10 North Broadway Avenue, will be ... 6.0 hours of relevant, practical instruction in the management of chronic pain. , ...
(Date:3/23/2017)... , ... March 23, 2017 , ... 82% of adults are unaware of the dangers ... not brush their teeth the minimum two times a day that dentists recommend. The ramifications ... 51 million hours of school and adults missing 164 million hours of work each year ...
Breaking Medicine News(10 mins):
(Date:3/23/2017)... , March 23, 2017 The key ... population, increasing diabetic population, accelerating economic growth and increasing healthcare ... industry are higher life expectancy of ESRD patients, rising demand ... markets. However, the expansion of the market is hindered by ... ...
(Date:3/23/2017)... , March 23, 2017  Transportation Insight, a ... an end-to-end supply chain management firm with expertise serving ... Product Solutions Rick Zaffarano was named a ... the Supply Chain by the only publication exclusively dedicated ... food supply chain. "Rick has brought to ...
(Date:3/23/2017)... INDIANAPOLIS , March 23, 2017  Eli ... the William Sansum Diabetes Center have established a research ... by diabetes through enhanced research, education and care. ... disease bears a disproportionate weight on Latino families in ... David Kerr , M.D., FRCPE, director of Innovation and ...
Breaking Medicine Technology: