Navigation Links
Cracking the egg

Sexual reproduction is not necessarily sexy (especially when scientists start analyzing it), but it is fascinating. As we all know, the basics entail bringing together an egg and a sperm, a whole lot of cell division and growth, and sooner or later a young organism that carries a mix of genes from both parents. There are many startling events along the way, but one of the most fundamental and important is the transition from unfertilized egg to fertilized embryo.

Think about it: The former is and will remain an egg if left alone, while the latter has within it the means to unleash the dazzling cascade of events needed to create a viable organism. What's already in the egg that enables it to make the transition? How is it the same and how is it different across species? And what changes occur when the egg is fertilized? Scientists led by Drs Barbara Knowles and Alexei Evsikov at The Jackson Laboratory have certainly been thinking about this topic for years. A new paper in the journal Genes & Development presents significant new information about what is happening within a fully grown (pre-ovulatory) egg and some of the changes that occur during transition to the two-cell stage embryo.

The researchers performed a large-scale survey of thousands of fragments of mouse egg cDNA. The cDNA fragments are reverse coded from messenger RNA and therefore indicate which genes are being expressed. They identified 5,400 active genes in the fully grown egg, about a tenth of which are unique to egg cells. Interestingly, the process of getting ready for fertilization requires more genetic activity than early embryo development. There's a far greater diversity of RNAs in the egg cell than in the two-cell embryo, perhaps because the embryo is independent and the pre-ovulatory egg must still coordinate signals with surrounding tissues.

Another discovery was that 80% of the expressed genes identified in mouse eggs are also expressed in the eggs of two other organisms previously studied, a frog and a sea squirt. Obviously early development is a very stable process and many of the crucial steps associated with it have remained the same along the vertebrate evolutionary pathway. But at the same time there's evidence of instability in other areas.

According to Dr. Evsikov, "There's tantalizing evidence for rapid change in a few critical mammalian genes specifically expressed in eggs. These fast-paced changes may pinpoint the molecular mechanisms for reproductive isolation, a primary cause for the origin of new species, and an astonishing diversity of mammals inhabiting Earth."


'"/>

Source:Jackson Laboratory


Related biology news :

1. Cracking the olfactory code in bees
2. Cracking the perception code
3. Cracking the genetic code for control of gene expression
4. Cracking open the black box of autoimmune disease
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:1/30/2017)... SAN FRANCISCO , Jan. 30, 2017   ... of the fastest growing genetic information companies, today announced ... 2016 financial results and provide 2017 guidance on Monday, ... a conference call that day at 4:45 p.m. Eastern ... call, Invitae,s management team will briefly review financial results, ...
(Date:1/26/2017)... -- Acuity Market Intelligence today released the 2017 "Ten ... characterizes 2017 as a "breakout" year for biometrics ... new understanding of the potential benefits these technologies ... are often perceived as threats to privacy and ... Acuity Market intelligence. "However, taken together these technologies ...
(Date:1/24/2017)... , Jan. 24, 2017 Biopharm Reports ... the laboratory use of nuclear magnetic resonance spectroscopy ... end-users and profiled current practices, developments, trends and ... well as growth and opportunities. These areas include ... NMR instruments, needs and innovation requirements, hyphenated NMR ...
Breaking Biology News(10 mins):
(Date:2/21/2017)... ... ... Creation Technologies, a private company and 25-year leader in ... today announced it has received the ‘Highest Overall Customer Rating’ Service Excellence Award. ... electronics manufacturing services (EMS) providers with annual revenues over $500 million. The award ...
(Date:2/21/2017)... 2017   Logicalis Healthcare Solutions , the healthcare-focused ... managed services provider ( www.us.logicalis.com ), today announced a ... The new service will help hospital CIOs make the ... physicians, nurses and other clinicians immediate access to a ... will allow hospital IT staff to focus on broader ...
(Date:2/21/2017)... 2017 Research and Markets has announced the ... Trends - Industry Forecast to 2025" report to their offering. ... The Global ... of around 12.8% over the next decade to reach approximately $8.9 ... market estimates and forecasts for all the given segments on global ...
(Date:2/20/2017)... Feb. 20, 2017  This Report analyzes the worldwide markets for ... The report provides separate comprehensive analytics for the US, ... , Asia-Pacific , Latin America ... full report: http://www.reportlinker.com/p04707099-summary/view-report.html ... Annual estimates and forecasts are provided for the ...
Breaking Biology Technology: