Navigation Links
Scientists unpick genetics of first 15 minutes of life

Scientists have identified the gene responsible for controlling a first key step in the creation of new life, according to new research published in the journal Nature tomorrow (Thursday 27 October 2005).

The gene, known as HIRA, 'chaperones' the early processes that take place once a sperm enters an egg, giving it a crucial role in the most fundamental process in sexually reproducing animals.

The absence or mutation of this gene in the maternal (mother's) genome explains why eggs fail to produce a zygote - or early embryo - despite the presence of 'healthy' sperm.

Although the researchers use the fruit fly Drosophila melanogaster to discover the basic genetic processes of sex, the same genetic processes are present in all sexually reproducing animals, including humans.

"All sexually reproducing animals do the same kind of DNA 'dance' when the DNA from the mother's egg cell and the father's sperm cell meet for the first time," said Dr Tim Karr from the University of Bath (UK) who worked closely with Drs Benjamin Loppin and Pierre Couble from Centre de G�n�tique Mol�culaire et Cellulaire (France) on the project.

"When the sperm enters the egg, the DNA it carries needs to be re-packaged so that it can engage in normal cellular activities, including combining with the maternal DNA in the first act of genetic fertilisation.

"A single gene, HIRA, looks after this re-packaging process, making it fundamental for those first 15 minutes in the regeneration of a new life."

When sperm cells are created, the molecule that the sperm DNA is wrapped around (called chromatin) is remodelled by swapping the type of 'packing material', known as histone proteins, it contains.

When it arrives at the egg cell, however, the sperm DNA needs to be re-packaged with a new set of histone proteins so that the sperm DNA can engage in normal cellular activities. The result is called the male pro-nucleus.

To understand how this process occurs, the researchers used a type of mutant fruit fly, known to biologists as a s�same mutant, which they know does not form a proper male pro-nucleus.

By highlighting the chromatin and watching the changes it goes through at different stages of the fertilisation process, the scientists found that the pro-nucleus in s�same mutant is wound into a tight ball that could not interact with its female counterpart, the egg pro-nucleus.

This showed that there was a problem with the re-packaging process in the s�same mutant.

The researchers looked at the genetic makeup of the s�same mutant and identified what is known as a point mutation in the HIRA gene ?showing that HIRA is the gene responsible for chaperoning the assembly of the sperm pro-nucleus.

"This is one of the most crucial process that takes place in sexually reproducing animals," said Dr Karr who works in the Department of Biology and Biochemistry at the University of Bath.

"Sperm DNA has to undergo a complete transformation when it arrives in the egg cell so that it can properly join with the female pronucleus to form a new genetically complete the beginning of a new life.

"A slight mutation in the HIRA gene means that life does not even get started.

"Amazingly we still know relatively little about the structure of sperm DNA and the genetic processes involved in the most crucial early phases of reproduction."

Because of the particular type of histone protein used in the re-packaging of sperm DNA, the researchers believe that this process leaves its mark in the genome of the newly-formed organism.

This genetic marker could be a useful way of tracking the genetic material an offspring inherits from either their father or mother.


'"/>

Source:University of Bath


Related biology news :

1. Scientists ID molecular switch in liver that triggers harmful effects of saturated and trans fats
2. Scientists Replicate Hepatitis C Virus in Laboratory
3. Scientists detect probable genetic cause of some Parkinsons disease cases
4. Scientists find missing enzyme for tuberculosis iron scavenging pathway
5. Scientists seek answers on what activates deadly anthrax spores
6. Yale Scientists Find MicroRNA Regulates Ras Cancer Gene
7. Scientists collaborate to assess health of global environment
8. Scientists decipher genome of fungus that can cause life-threatening infections
9. Scientists discover the cellular roots of graying hair
10. Scientists rid stem cell culture of key animal cells
11. Scientists develop new color-coded test for protein folding
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/31/2016)... March 31, 2016  Genomics firm Nabsys has completed ... Barrett Bready , M.D., who returned to the ... original technical leadership team, including Chief Technology Officer, ... Development, Steve Nurnberg and Vice President of Software and ... company. Dr. Bready served as CEO of ...
(Date:3/21/2016)... Unique technology combines v ... security   Xura, Inc. ... digital communications services, today announced it is working alongside ... customers, particularly those in the Financial Services Sector, the ... within a mobile app, alongside, and in combination with, ...
(Date:3/14/2016)... -- NXTD ) ("NXT-ID" or the "Company"), a ... airing of a new series of commercials on Time Warner ... st .  The commercials will air on Bloomberg TV, Fox ... Street show. --> NXTD ) ("NXT-ID" or the ... announces the airing of a new series of commercials on ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... 2016 Elekta is pleased to ... its industry-leading treatment planning software, is available for clinical ... version 5.11 provides significant performance speed enhancements ... up to four times faster than in previous versions ... gold standard Monte Carlo algorithm, ...
(Date:4/28/2016)... 2016 Q BioMed Inc. ... CEO  was featured in an article he wrote ... Fear To Tread: http://www.lifescienceleader.com/doc/accelerators-enter-when-vcs-fear-to-tread-0001 ... is an essential business journal for life science ... to Big Pharmas. Their content is designed to ...
(Date:4/28/2016)... (PRWEB) , ... April 28, 2016 , ... ... Asymmetrex will deliver a talk on its first-in-class technologies for tissue stem ... 2016 Meeting on RNAiMicroRNA Biology to Reprogramming & CRISPR-based Genome Engineering in ...
(Date:4/28/2016)... , ... April 28, 2016 , ... ... will hold an open house for regional manufacturers at its Maple Grove, Minnesota ... Tsugami, Okuma, Hardinge Group, Chiron and Trumpf. Almost 20 leading suppliers of ...
Breaking Biology Technology: