Navigation Links
Mother birds increase progesterone to hatch females

In mammals, sperm from the male determines the sex of the offspring. In birds, however, it is the female's sex chromosome that determines offspring sex. Now, Cornell University researchers think they understand the mechanism that several bird species use to bias the sex ratios of their offspring toward female.

By experimenting with domestic chickens, they have determined that the presence of higher-than-normal levels of the hormone progesterone during the first meiosis -- the cell division that divides the sex chromosomes and genetically determines the sex of an offspring -- produces significantly more females.

"For years, behavioral biologists have been trying to figure out how the females of a few species, such as the Seychelles warbler, the zebra finch and tree swallow, adaptively manipulate the sex of their offspring before an egg is laid," says Stephanie Correa, a doctoral student in neurobiology and behavior at Cornell and the lead author of the study that was posted online recently in The Royal Society's Biology Letters (Vol. 1, 2005). "Most investigators have looked primarily at testosterone, but we decided to look at progesterone, the major hormone produced by the female bird's preovulatory follicle."

To test the influence of progesterone on the sex ratio of offspring, Correa, along with Elizabeth Adkins-Regan, professor of neurobiology and behavior and of psychology, and Patricia Johnson, professor of animal science, both at Cornell, experimentally manipulated levels of progesterone in female chickens during the first meiosis. They injected either a low dose or a high dose of progesterone (dissolved in sesame oil) or a control dose of pure sesame oil.

The low dose of progesterone produced 61 percent males, which was very close to the control group rate of 63 percent males. The high dose of progesterone, however, produced only 25 percent males.

"Thus, we think that how much progesterone the female follicle produces dur
'"/>

Source:Cornell University News Service


Page: 1 2

Related biology news :

1. Antiretroviral Therapy May Prevent HIV Transmission From Breastfeeding Mothers To Infants
2. Mother birds give a nutritional leg up to chicks with unattractive fathers
3. Mother knows best: Plant knowledge key to childhood health in remote Amazon
4. Migratory songbirds have a specialized night-vision brain area
5. The lopsided brain: Attention bias is shared by humans and birds
6. Bobbing birds do it for a reason
7. Overbearing colored light may reveal a second mechanism by which birds interpret magnetic signals
8. Industrial contaminants spread by seabirds in High Arctic, new Canadian study shows
9. Displaced songbirds navigate in the high Arctic
10. Oil spills and climate change double the mortality rate of British seabirds
11. Wild birds help to create human flu vaccine
Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Mother birds increase progesterone hatch females

(Date:1/22/2015)... , Jan. 22, 2015 Research and Markets ... of the "Global Wearable Technologies Market and ... Overview, Trends and Forecast 2014-2020" report to ... are smart devices that can be worn on ...
(Date:1/22/2015)... CHARLOTTE, N.C. , Jan. 22, 2015 Infinisource has ... introduction of the G2 model. The G2 sets a higher ... company,s iSolved human capital management solution. With plug-and-play installation, touch ... G2 time clock provides a robust time collection solution for ...
(Date:12/22/2014)... 2014  NXT-ID, Inc. (NASDAQ: NXTD and NXTDW) ... the growing mobile commerce market, announces it has retained famous ... the 2015 International CES debut of the Wocket™ biometric smart ... at the NXT-ID booth January 6th and 7 th , ...
Breaking Biology News(10 mins):Global Wearable Technologies Market and Applications, Opportunities, Industry Analysis, Segmentation, Size, Growth, Share, Overview, Trends and Forecast 2014-2020 2Infinisource's NXG series sets new time clock standard 2NXT-ID Hires Master Pickpocket and Security Consultant Apollo Robbins for Wocket Smart Wallet CES 2015 Debut 2NXT-ID Hires Master Pickpocket and Security Consultant Apollo Robbins for Wocket Smart Wallet CES 2015 Debut 3NXT-ID Hires Master Pickpocket and Security Consultant Apollo Robbins for Wocket Smart Wallet CES 2015 Debut 4
... Biophysical Society is pleased to announce that it will ... with the International Biophysics Congress in Long Beach, California, ... talks and poster sessions that take place during the ... to discuss current policy issues facing our nation. The ...
... New research at the University of Chicago finds evidence ... the pain of loneliness: They create people in their ... not a very efficient way to alleviate ones loneliness, ... to do so, said Nicholas Epley, Assistant Professor of ...
... This release is also available in French . ... to community involvement today with a $1-million donation to ... and Hospital (MNI), affiliated with McGill University and the ... $40-million initiative to invest in people and expand facilities ...
Cached Biology News:Biophysical Society to host discussions on the teaching of evolution and on the energy crisis 2People not always needed to alleviate loneliness 2People not always needed to alleviate loneliness 3Building the future -- 21st century nano tools to repair the nervous system 2
(Date:1/22/2015)...   Cypher Genomics, Inc., the leading genome ... SQNM ), the leading molecular diagnostics company, today ... prenatal tests (NIPT). Through this agreement, Sequenom will ... advance analysis of clinically-relevant fetal sub-chromosomal variants detected ...
(Date:1/22/2015)...  Derma Sciences, Inc. (Nasdaq: DSCI ), ... care, announces that AMNIOEXCEL® and AMNIOMATRIX®, amniotic allografts ... the Premier, Inc. Regenerative Skin Grafting contract portfolio. ... and AMNIOMATRIX® product lines, which continue to be ...
(Date:12/24/2014)... NEW YORK , Dec. 24, 2014 PlasmaTech ... care in critical areas, announced the closing of an underwritten ... to purchase up to an aggregate 3,500,000 shares of common ... $.01 per warrant.  The warrants have a per share exercise ...
(Date:12/24/2014)... 23, 2014 “Preparative & Process ... Flash), Consumables (Columns, Solvents, Buffers, Valves, Guages, Seals), ... Agriculture) - Forecasts to 2019” provides a detailed ... current market trends, and strategies impacting the preparative ...
Breaking Biology Technology:Cypher Genomics and Sequenom Announce Development Agreement 2Cypher Genomics and Sequenom Announce Development Agreement 3Cypher Genomics and Sequenom Announce Development Agreement 4Derma Sciences Expands Access of its AMNIOTIC TISSUE Product Line with New Premier, Inc. Agreement 2Derma Sciences Expands Access of its AMNIOTIC TISSUE Product Line with New Premier, Inc. Agreement 3Derma Sciences Expands Access of its AMNIOTIC TISSUE Product Line with New Premier, Inc. Agreement 4Derma Sciences Expands Access of its AMNIOTIC TISSUE Product Line with New Premier, Inc. Agreement 5PlasmaTech Biopharmaceuticals, Inc. Announces Closing of Public Offering 2PlasmaTech Biopharmaceuticals, Inc. Announces Closing of Public Offering 3Preparative and Process Chromatography Market is expected to reach $9 billion by 2019 - New Report by Marketsandmarkets 2Preparative and Process Chromatography Market is expected to reach $9 billion by 2019 - New Report by Marketsandmarkets 3Preparative and Process Chromatography Market is expected to reach $9 billion by 2019 - New Report by Marketsandmarkets 4
... U.S. Biogeneric Agents to Reach $2 Billion in Sales by 2016, ... New ... Resources, Inc., one,of the world,s leading research and advisory firms for ... with biologic sales of more than $14 billion in 2006, and ...
... States Boyden Global Executive Search ,Helps Businesses Find the ... ... Boyden Global Executive Search of,Summit is featured in the September ... of the New Jersey Business and,Industry Association (NJBIA), the largest state ...
... N.C., Sept. 5 A study in ... the use of the GlycoMark,1,5-anhydroglucitol (1,5-AG) blood ... especially to target postprandial hyperglycemia (elevated,after-meal glucose ... achieving optimal glycemic control and reducing the ...
Cached Biology Technology:Amgen and Genentech Brace Themselves for Heavy Pressure From Biogenerics Manufacturers 2Boyden's Summit Practice Featured in the September Issue of New Jersey Business Magazine 2Study Supports Use of GlycoMark Blood Test to Evaluate Therapy in Children with Diabetes 2
The LIC Duet™ Mini Adaptor encodes a T7 promoter, lac operator, ribosome binding site (rbs), and an ATG translation initation codon. This adaptor is designed for expression of a target protei...
... these culture chambers produce cell yields in ... range and are useful alternatives to multiple ... mechanical • strength and structural integrity • ... Certified nonpyrogenic and sterilized by gamma irradiation, ...
ABgene® supplies a 94kDa ultra-pure recombinant thermostable DNA polymerase obtained by high level expression of the Taq DNA polymerase gene in E. coli....
...
Biology Products: