PROJECT : AMELIGEN | Using genetics to improve the pearl oyster
Pinctada margaritifera in French Polynesia
KEY REQUIREMENTS & QUALIFICATIONS. The Population Genetics Postdoctoral
Position will be based at the CRIOBE, splitting his/her time between
the laboratories in Perpignan, France and at the Centre in Moorea,
French Polynesia. The position will be co-supervised by Dr. Serge
Planes (CRIOBE) and Dr. Chin-Long KY (Ifremer, Tahiti).
The successful candidate has a background in population genetics, both
in the laboratory setting (processing and screening samples) and in
theory, with experience in the development of population genetic
models. In addition, the successful candidate has experience in the
construction of genetic linkage maps, QTL identification and a strong
background in the use of bioinformatic tools. Field experience is
desired, for the acquisition of data for both cultured pearl quality
and oyster biometric growth traits. See context and detailed objectives
below for more details on required competencies.
PROJECT CONTEXT. The development of highly variable molecular markers
like microsatellite DNA, has improved fine-scale population genetics
research. Being able to estimate population structure as well as gene
flow between populations is important when considering the implications
for conservation. Humans exploit a large number of species that can
have devastating impacts on biodiversity. To address this threat, the
number of studies that focus on conservation genetics needs to be
enhanced, and within these studies, we need to ensure that appropriate
genetic markers are developed.
The black-lipped pearl oyster, Pinctada margaritifera in French
Polynesia, provides an interesting case for the study of habitat
fragmentation effects on genetic diversity and connectivity in marine
organisms. P. margaritifera has traits commonly associated with
panmixia, or weak genetic structure (Blanc 1983; Durand and Blanc 1988;
Arnaud-Haondet al. 2002; Arnaud-Haondet al. 2004; Arnaud-Haondet al.
2008), is protandrous, relatively long-lived (< 20 years), iteroparous
with high fecundity, and externally fertilizes gametes through
broadcast spawning and has a long-lived larval dispersal stage (over 21
days; Saucedo & Monteforte 1997). However, even considering these
attributes, , the sedentary nature of the adult and its confinement to
island and atoll lagoons or sheltered coves is indicative of population
fragmentation.
The pearl oyster, P. margaritifera, is the most commercially important
shellfish, and is cultured for pearl production in French Polynesia
(Gervis & Sims 1992, Sarver & Sims 1996). Since 1970, the pearl
industry has become a major economic resource in French Polynesia,
producing up to 8000 kg of pearls per year (Coeroli 1983, Intes 1984).
As a commercial species, knowledge of genetic structure is important
for delineating management units and maintaining sustainable
aquaculture. The French Polynesian pearl-oyster farms rely exclusively
on wild spat collection, making the activity dependant on natural
stocks (Coeroli et al. 1984). Spats are collected from lagoons with
high recruitment (mainly in the Tuamotu and Gambier archipelagos) and
are translocated to pearl farms throughout the territory (Le Pennec
2010), creating artificial gene flow across archipelagos (Lemer and
Planes 2012). Most of these translocations have been reported through
the French Polynesian Department of Fisheries enabling us to identify
the remaining lagoons with wild and pristine stocks of P. margaritifera
not affected by translocation (mainly uninhabited atolls).
Since 2013, multidisciplinary research projects on the different
populations of P. margaritifera found throughout the lagoons of French
Polynesia have been conducted, with a focus on the following :
1. Exploit and manage the genetic diversity of the resources.
2. Start genetic selection for colour and growth, the two main-traits
of interest (Ky et al., 2017).
3. Understand the mechanisms at the origin of the phenotypic expression
(plasticity) in relation to environmental variations (Ky et al., 2017).
4. Study the genome through next generation sequencing technologies.
This Postdoctoral Position will be a part of this global genetic
improvement program for P. margaritifera.
PROJECT OBJECTIVES. Traditional markers, like allozymes, mitochondrial
DNA, and even microsatellites have shown limitations when studying
conservation genetics at the intra-specific level (Hedrick 2001;
Jarne&Lagoda 1996; Schlotterer 2004; Sunnucks 2000). When addressing
questions about how cultured animals deal with selection, the impacts
of cultured animals on wild stocks, or the genetic component of
phenotypic plasticity, there is a clear need to establish a stable set
of markers that are widely distributed throughout the genome, and that
allow access to inter-specific variability. Recently, Single Nucleotic
Polymorphisms (SNP) have been developed and applied, providing a broad
overview of the genome variability.
Key Objectives:
1. Develop a standardized SNP screening protocol for the pearl oyster,
P. margaritifera;
2. Use this set of SNPs to screen the genetic variability of different
(natural and hatchery produced) populations of P. margaritifera;
3. Generate several genetic linkage maps of P. margaritifera G2
families for both cultured pearl quality trait QTL identification and
for genome (currently under assembly) construction.
HOW TO APPLY
Interested applicants should send a cover letter, a statement of
research goals and a CV to planes@univ-perp.fr. Applicants will receive
an e-mail confirming their application has been received.
CLOSING DATE
All applications should be submitted by 30 June 2017. However, until
the position is filled, we will continue to accept application
materials.
Emilie Boissin
Post-doctoral researcher
USR3278-CRIOBE-CNRS-EPHE-UPVD
Laboratoire d’excellence “CORAIL”
Universite de Perpignan-CBETM
58 Rue Paul Alduy
66860 Perpignan CEDEX
France
Emilie Boissin <eboissin@gmail.com>