Dr.
Amro Zayed
Assistant Professor
Department of Biology
York University
4700 Keele Street
Toronto, ON M3J 1P3 Canada
Email: zayed[at]yorku.ca
I am pleased to announce that I will be starting a faculty position at York University’s Department of Biology (Toronto, Canada) during the summer of 2009, where I will continue my research on the evolutionary genomics of bees. My laboratory will provide graduate students and postdoctoral fellows with an integrative environment to conduct research at the intersection of ecology, evolution, and genomics, utilizing the latest technology (e.g. microarrays, SNPs, next-generation sequencing, etc.). Funding is available for several graduate students. If you are interested in joining my laboratory, please email me your CV and a statement of research interests.
Please visit my faculty webpage at York U for the latest research news.
Sincerely, Amro
Academic Background:
Ph.D. Biology, York University
(Toronto, Canada)
Research Interests: I am broadly interested in how
genetic diversity - diversity at the lowest form of biological
organization - affects individual, population and community
level traits at both ecological and evolutionary time scales.
I prefer to take an interdisciplinary approach to research
by integrating theoretical and modeling exercises with empirical
and experimental (when possible) studies, utilizing population
genetics, molecular biology, genomics, and ecological methods.
Postdoctoral Research: I am currently conducting
research in Dr.
Charlie Whitfield's lab at the University of Illinois
at Urbana-Champaign. We are attempting to study the genetic
basis of division of labor in Honeybee colonies using a
'systems' approach combining quantitative genetics (quantitative
trait mapping) and genomics (to measure global gene expression
- the first phenotype!). Division of labor, or 'task' specialization,
is an important feature of insect colonies, and likely at
the root of their ecological dominance. In the honeybee,
workers undergo an age-related shift in behavior, from in-hive
tasks such as nursing to outside tasks such as collecting
pollen and nectar. We hope to show how genetic variation
influences a complex trait such as division of labor through
intermediate phenotypes (such as gene expression, physiology).
In the meantime, Dr. Whitfield and I recently published
a paper showing that positive selection has facilitated
adaptation in natural and invasive honey bee populations
[article,
press
release, USA
Today article, Inside
Illinois Story, John
Hawks' blog].
Doctoral Research: My Ph.D. dissertation, supervised
by Dr. Laurence Packer,
focused on bee population and conservation genetics. Why
bees? They are the principal pollinators in almost all terrestrial
ecosystems, and they play a major role in agricultural systems
as well... Bees pollinate about 70% of the crops that feed
the world, generating billions of dollars annually !!!...
Pollination has been highlighted as a degraded ecosystem
service in the latest Millennium
Ecosystem Assessment: declines in pollinator populations
have been reported worldwide. We need to research methods
of protecting and conserving bee populations.
My thesis mainly involved how sex determination affects
the population biology of bees, ants and wasps. In bees,
a strange and unique phenomenon can sometimes occur due
to complementary sex determination - the production of diploid
males. Male bees are usually haploid, but under certain
circumstances (involving inbreeding or loss of allelic diversity
in small populations) diploid males are produced instead
of females (see Figure 1). Diploid
males do not reproduce or help around in the nest, so their
production is highly disadvantageous. Through a modeling
study, we discovered that the production of diploid males
GREATLY increases the extinction risk in small bee populations
(see article ,
also see Toronto Star article,
TVO's interview, Radio
Canada interview, press
release, Y-File, NSERC
Story, Research
Focus feature in Trends in Ecology and Evolution by P. Hedrick,
J. Gadau and R.E. Page Jr.). Further, my colleagues
and I have proposed the use of diploid male production as
a parameter to indicate pollinator decline (see
article, also see press
release, PRSL Summary, feature
on Y-File, York
U article). I also plan on examining the effects of
diploid male production on bee metapopulaion dynamics, both
theoretically and empirically.
I also examined the effects of pollen specialization on
the population genetics of oligolectic bees. Oligolectic,
or specialist bees collect pollen from only a specific flower
taxon. Polylectic bees, on the other hand, collect pollen
from many taxa. Oligolectic bees might be expected to persist
in smaller and more isolated populations than polylectic
bees. We have recently found evidence supporting this hypothesis
(see article,
also see Excalibur story).
In a study of specialist and generalist bees in Chile, we
found that specialist bees have lower levels of genetic
diversity when compared to closely related generalists,
which is indicative of specialists persisting in smaller
effective populations. We also found higher levels of genetic
differentiation within populations of a specialist bee when
compared to a generalist, implying that specialists live
in more isolated populations (see
article). Significant population structure has also
been found in a North American evening primrose specialist
(Zayed and Packer,
2007) using newly developed microsatellite markers for
the bee genus Lasioglossum (Zayed
2006).
If you have any questions and comments on my research,
please contact me. Thanks for visiting my site.
Amro Zayed, Ph.D.
zayed[at]yorku.ca
Publications:
12. Zayed, A., Whitfield, C.W. (2008). A genome-wide signature
of positive selection in ancient and recent invasive expansions
of the honey bee Apis mellifera. Proceedings of the
National Academy of Sciences USA, 105:3421-3426. [article,
press
release, USA
Today article, Inside
Illinois Story, John
Hawks' blog]
11. Zayed, A., Constantin, S.A. and Packer, L. (2007) Successful
biological invasion despite a severe genetic load. PLoS
ONE 2:e868. doi:10.1371/journal.pone.0000868. [article,
press release, Conservation
Magazine story]
10. Zayed, A., and Packer L. 2007. Population genetics
of a solitary oligolectic sweat bee, Lasioglossum
(Sphecodogastra) oenotherae (Hymenoptera:
Halictidae). Heredity, 99: 397-405. [pdf]
9. Zayed, A. 2006. Characterization of microsatellite loci
from the solitary sweat bees Lasioglossum leucozonium
and Lasioglossum oenotherae (Hymenoptera, Halictidae).
Molecular Ecology Notes, 6: 1154-1156. [pdf]
8. Zayed, A., and Packer, L. 2005. Complementary sex determination
substantially increases extinction proneness of haplodiploid
populations. Proceedings of the National Academy of Sciences
USA, 102:10742-10746.[pdf,
Toronto Star article, TVO's
interview, Radio Canada interview,
press release, Y-File,
NSERC
Story, Research
Focus feature in Trends in Ecology and Evolution by P. Hedrick,
J. Gadau and RE Page Jr.]
7. Zayed, A., Packer, L., Grixti, J.C., Ruz, L., Toro,
H., and Owen, R. 2005. Increased genetic differentiation
in a specialist versus a generalist bee: implications for
conservation. Conservation Genetics, 5:1017-1026. [pdf]
6. Packer, L.*, Zayed, A.*, Grixti, J.C., Ruz, L., Owen,
R., Vivallo, F., and Toro, H. 2005. Conservation genetics
of potentially endangered mutualisms: reduced levels of
genetic variation in specialist versus generalist bees.
Conservation Biology. 19:195-202. [pdf,
Excalibur story]
* L. Packer and A. Zayed contributed
equally to this paper.
5. Zayed, A. 2004. Effective population size in Hymenoptera
with complementary sex determination. Heredity, 93:627-630.
[pdf]
4. Zayed, A., Roubik, D.W., And Packer, L. 2004. Use of
diploid male frequency data as an indicator of pollinator
decline. Proceedings of the Royal Society of London B. 271,
S9-S12. [pdf, press
release, PRSL Summary, feature
on Y-File, York
U article]
3. Grixti, J.C., Zayed, A., and Packer, L. 2004. Behavioral
interactions among females of Acamptopoeum submetallicum
(Spinola) and Nolanomelissa toroi Rozen (Hymenoptera:
Andrenidae). Journal of Hymenoptera Research. 13:48-56.
2. Zayed, A. and Packer, L. 2002. Genetic differentiation
across a behavioural boundary in a primitively eusocial
bee, Halictus poeyi Lepeletier (Hymenoptera: Halictidae).
Insectes Sociaux, 49:282-288. [pdf]
1. Zayed, A. and Packer, L. 2001. High levels of diploid
male production in a primitively eusocial bee (Hymenoptera:
Halictidae). Heredity, 87:631-636. [pdf]