Molecular control of sex determination and gonadal development.

Mechanisms underlying sexual dimorphisms in birds.

Micro-RNA regulation of cell and tissue differentiation.

Co-ordinator of RICE (Roslin Institute Chicken Embryology) Group

Organiser for 'avian' module of MSc in Animal Biotechnology

Member of the R(D)SVS Postgraduate Committee

Member of The Roslin Institute Quality Management Committee

PhD-committee member for Edinburgh University

Our findings overturned a long-standing dogma and demonstrated that a system of sex chromosome dosage compensation operated in birds. We were also the first group to demonstrate that gynandromorph birds are composed of normal diploid male and female cells, and this helped to establish that the mechanisms and factors that regulate the development of the sexual phenotype differ between mammals and birds. We have shown that, unlike mammals, avian somatic cells possess a cell-autonomous sex identity (CASI), and that CASI is the major determinant in defining the sexual phenotype. We have demonstrated that male and female cells respond differently to extracellular signals (hormonal and developmental). We have identified a set of genes that are expressed differently in male and female cells from the point of fertilisation through to adulthood. These genes are expressed in a sexually dimorphic fashion in all tissues at all stages of development, and are likely to represent the molecular signature underlying the inherent sex-identity that we identified in avian cells. Here we show that this inherent sex-identity can be 'short-circuited' by perturbing intracellular signals. Most significantly, we demonstrate that cells of the male and female immune systems are different: female cells are effectively pre-primed to respond to infection and this may account for the sex-related differences seen in mortality rates due to infection. We have also identified morphological and molecular differences in the embryonic development of male and female skeletal muscle. We believe that establishing this sexual dimorphism during embryonic development is the key reason for the difference in muscle mass between sexually mature male and female birds. A thorough understanding of this mechanism may provide a means of selecting larger female birds and thereby increasing poultry meat production. We have also developed an in-ovo sexing assay that fully meets the timing and cost requirements of the poultry industry. This assay can identify the sex of chick embryos from nanolitre volumes of whole blood in under five minutes, and if successfully applied, this procedures will lead to increases in food production and will address a significant poultry welfare issue.

• 1974-1978. Developmental Biology Honours 2:1 Aberdeen University

• 1979-1982. Ph.D. Department of Biochemistry. Aberdeen University (The role of extracellular matrix components in ovarian follicular development).

• 1992-Present Group Leader, Roslin Institute.

• 1990-1992. Division of Eukaryotic Molecular Genetics, MRC-National Institute for Medical Research (NIMR), Mill Hill, London

• 1987-1990. Department of Biochemistry, Cornell University Medical College, 1300 York avenue, New York, USA

• 1983-1986. Department of Medical Microbiology, Aberdeen University

• 1974-1978. Developmental Biology Honours 2:1 Aberdeen University

• 1979-1982. Ph.D. Department of Biochemistry. Aberdeen University (The role of extracellular matrix components in ovarian follicular development).

   

Adam Balic group

Denis Headon group

Mike McGrew group

Megan Davey group

Helen Sang group

Tom Burdon group

Xavier Donadeu group

Neil Mabbot group

David Hume Group

David Argyle group

Sarah Taylor Group

Brendan Corcoran group

Katia Marioni-Henry group

Yolanda Martinez-Periera group

Silvana Guioli and Robin Lovell-Badge at The FRancis Crick Institute in London

Pasqualino Loi at Teramo University, Teramo, Italy

PhD Students

L Haines 1998

A McLaren 1998

G Meile 1999

I Stylianou 2004

L Bailey 2011

S Aungier 2014

C Hunter 2016

MSc Students

Y Hu Current

H Sulong 2016

B Schultz 2016

M Ramuz 2015

D Hart 1996