Tue, 23 Apr 2013: 1.00pm @ DBS CR II – Zhang Manping on “Population Structure and Gut Flora Diversity in Coptotermes gestroi in Southeast Asia”

ZMP

Qualifying  Examination

“Population Structure and Gut Flora Diversity in Coptotermes gestroi in Southeast Asia”

Zhang Manping
Graduate Student
Dept. of Biological Sciences, NUS

Tues, 23 April 2013: 1.00pm
@ DBS Conference Room ii (S1 Level 3, Mezzanine)
Supervisor: Assoc Prof Evans, Theodore Alfred

All are welcome

Abstract:

Coptotermes gestroi (Wasmann) (Insecta: Isoptera: Rhinotermitidae), commonly known as the house termite, is one of the most destructive urban pests in Southeast Asia.  This species has gut microorganisms (protists, bacteria and archea) to aid wood digestion and nutrient intake. 

It appears to be an urban adaptor or exploiter, as it rare in natural forests, but common in urban centres; it has been found to infest up to 80% of buildings in Malaysia.

The species is invasive as well, and had spread though human trade to other geographic regions, including east and south Asia, North and South America, Europe and several islands in the Pacific, Caribbean and India Oceans. 

Although C. gestroi is an important pest species, little is known about its origins, endemic distribution, geographic spread, and adaptation to urban life. Indeed it is only in the last decade its taxonomy was resolved.

My project aims at uncover some of this unknown information, by elucidating the population structure and genetic diversity of C. gestroi across Southeast Asia and invasive populations using microsatellite markers.  A better sampling strategy (sampling in cities, countrysides and forest) and comparative Copototermes species would be adopted. 

Pyrosequencing survey of the gut flora diversity will be used as a facilitated method to reveal the dispersal pattern, and help understand adaptation to urban life.

A laboratory experiment that tests the effect of food types on gut flora diversity of C. gestroi will complement the pyrosequencing. 

My project intends to shed some light on

  1. The origin and dispersal pattern of C. gestroi.
  2. The underlying mechanism for wide distribution of the species.
  3. The adaptive strategy of C. gestroi to urbanization.”

Fri, 19 Apr 2013, 10.30am @ DBS CF: Ng Ting Hui on “Investigating the introduction and impacts of gastropods in Singapore’s fresh waters”

Qualifying  Examination

“Investigating the introduction and impacts of gastropods in Singapore’s fresh waters”

Ng Ting Hui
Graduate Student
Dept. of Biological Sciences, NUS

Friday, 19 April 2013: 10.30am
@ DBS Conference Room (S3 L5)
Supervisor: Asst. Prof. Darren Yeo, Dr. Tan Heok Hui

All are welcome

Abstract:

“Introduction of freshwater gastropods are a concern globally owing to negative impacts like habitat-modification, competition with native species, and the spread of zoonotic parasites. In contrast to other native aquatic fauna in Singapore, which are usually found in unmodified habitats, freshwater molluscs here are almost exclusively found in human-impacted habitats, e.g., reservoirs and canals. Hence, it is suspected that many species may have been introduced. The lack of comprehensive information regarding native freshwater molluscs has made it difficult to determine the true status of many species found here. My inspection of museum collections and unpublished data found that only six species of gastropods were found here half a century ago, while the current malacofauna consists of 33 species, including freshwater bivalves. Preliminary data from a review of freshwater mollusc introductions to Southeast Asia shows that the aquarium trade has been most often proposed as a source for introductions, including in Singapore. A survey of the aquarium trade here revealed 58 species. While the results indicate that the trade is a likely introduction pathway, it is also implied that there are other potential pathways.

I also aim to investigate if the genetic diversity of local freshwater molluscs can resolve the status of cryptogenic species, and to examine the factors facilitating the spread of freshwater molluscs by investigating physico-chemical parameters and life history traits that may influence their distribution in canals. Finally, preliminary data indicates that the decline in distributions of native apple snail Pila scutata coincides with the introduction and spread of the confamilial golden apple snail Pomacea canaliculata. Potential ecological overlap between these two species will thus be investigated. The results of the genetic and ecological studies will be used to determine the management measures necessary to control introduced freshwater gastropods in Singapore.”

Tue 23 Apr 2013: 10.00am @ DBS CF – Pitta de Araujo, Diego on “Morphological and Chemical Evolution in Sepsidae”

diegoQualifying  Examination

“Morphological and Chemical Evolution in Sepsidae: An Evolutionary Approach to Phenomics and Shape Analysis”

Pitta de Araujo, Diego
Graduate Student
Dept. of Biological Sciences, NUS

Tues, 23 April 2013: 10.00am
@ DBS Conference Room (S3 Level 5)

Supervisor: Prof. Rudolf Meier
Co-SupervisorDr. Joanne Yew

All are welcome

Abstract:

“New advancements in morphological and chemical analysis are promoting a renaissance of the studies of phenotypes in the era of genomics. Here I propose to use a “phenomics” approach to fully explore the morphology and chemistry of Sepsidae flies. These flies have very complex and variable morphological structures most of which are used in sexual behaviour and serve as a model clade to study phenotypic evolution. I am combining several morphological imaging techniques (Visionary Digital, Light Microscopy, Confocal Microscopy and Scanning Electron Microscopy) and chemical imaging (Ultra-Violet Laser Desorption Ionization Mass Spectrometry) to understand key changes during sepsid evolution. The three main questions that be addressed in this research are: How much morphological and chemical change happened in the evolution of Sepsidae? Is there a phylogenetic pattern and correlation among different phenotypes? How to quantify morphological change in an evolutionary context?

I carried out a detailed morphological and chemical study of the mysterious osmeterium, a gland that is located on the hind tibia of males. I use UV-LDI Mass Spectrometry to solve the identity of its secretion, the time of secretion, and the secretion’s fate when it is transferred to the female’s body during mating. My preliminary morphological results pertain to the morphology of the head capsule and mouthparts and indicate variation among species, mainly with regard to the structure of the head capsule. For this part of the flies’ body there is little evidence for sexual dimorphism. The thorax morphology of sepsids varies among species with regard to the shape of thoracic plates and patches of micropilosity. I am also the first entomologist studying the male intromittent organ in sepsids and document its variation across the species.

Lastly, I propose to explore new tools in 3D design to create representations of morphological structures. I propose to use new techniques in shape analysis for advanced 3D visualization and shape measurement: evolutionary morphing, shape similarity and shape complexity. With these tools I hope to quantify and visualize how sepsid morphology changed over evolutionary time.”

Kathy Su’s paper on wingspot evolution in Science

Citation: Arnoult, L., Su, K. F., Manoel, D., Minervino, C., Magriña, J., Gompel, N., & Prud’homme, B. (2013). Emergence and Diversification of Fly Pigmentation Through Evolution of a Gene Regulatory Module. Science, 339 (6126): 1423-1426.


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Kathy Su obtained her Honours and Masters degrees at NUS has successfully completed her Ph.D. in France and is now back in Singapore to pursue her post-doctoral research at the Evolutionary Biology Lab.

Her doctoral research on the evolution of wing spot patterns in Drosophilid flies was recently published in the journal Science.

The study illustrated how the appearance of darkened wing spots within a group of closely related flies was orchestrated by the assembly of a gene regulatory network involving several pigmentation genes under the regulation of at least one shared transcription factor.

This study has broad implications and provides insights into the emergence of novel morphological traits and their subsequent diversification. Her study was also featured recently in the French press, Le Monde.

Congratulations Kathy on your recent publication!

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Tue 16 Apr 2013: 3.00pm – William Eckman on “Ecology and Restocking of Giant Clams”

Qualifying  Examination

“Ecology and Restocking of Giant Clams”

William Eckman
Graduate Student,
Dept. Biological Sciences, NUS

Tue 16 April 2013: 3.00pm
@ DBS Meeting Room
(S3 Level 5,General Office #05-010)

Supervisor: Asst Prof Peter Alan, Todd

All are welcome

Abstract:

“As giant clams inhabit shallow waters, primarily in developing nations, many of their species are in danger of becoming directly extirpated by human activity, or of being unable to reproduce due to falling population densities. Over their long lifespans, giant clams produce large numbers of offspring, which have low survival rates at the larval and juvenile level. This is a successful reproductive strategy in the absence of human intervention.

Archaeologists know that humans have been harvesting clams for thousands of years, but modern technologies such as commercial fishing boats and SCUBA gear are depriving clams of refugia from which to repopulate other reefs. Increasing water turbidity due to coastal development, eutrophication, and dredging can make deeper water uninhabitable to giant clams, forcing their populations to reestablish in areas where they are more vulnerable to harvesting, tropical storms, and increasing water temperatures.

There is a significant amount of scientific literature regarding giant clams, particularly regarding their anatomy, physiology, and their symbiotic relationship with zooxanthellae. However, there are major gaps in the areas of their general ecology, reproductive behavior, and larval stages.

I will present the results of my experiments to determine giant clam larval tolerances to elevated water temperature, reduced light penetration, and reduced salinity.

I will also outline a proposed general ecology paper which will highlight and attempt to quantify the role that giant clams play in maintaining healthy reef ecosystems. There have been attempts in many countries to restock reefs with giant clams, although success rates have been low. Those efforts have not documented their strategy for placing clams in order to achieve high rates of survival and reproductive success.

I have carried out some preliminary investigations into giant clam reproductive behavior, and will continue and expand that work into a model resulting in guidelines for optimal clam placement. Clams in restocking efforts are initially placed in anti-predator cages, but their design is haphazard. I will experimentally compare several designs, including intertidal, benthic, and floating models, to determine which is most suitable for clam protection and growth in Singapore’s waters.

Finally, I plan to investigate the impacts of sediments on giant clams, using machinery which is capable of varying the timing and intensity of sediments to simulate various environmental or anthropogenic events.”

Job: Manager at National Biodiversity Centre, NParks

Careers@Gov

Application details at NParks webpage.

Responsibilities

The Biodiversity Information and Policy branch under the National Biodiversity Centre is responsible for developing biodiversity information products and services, coordinating and promoting collaboration and partnerships in enhancing urban biodiversity and ecology in Singapore, driving the implementation of policies and guidelines pertaining to biodiversity conservation and managing the implementation of the National Biodiversity Strategy and Action Plan.

Key responsibilities

The successful applicant is required to facilitate and steer biodiversity research towards conservation priorities in support of Singapore’s National Biodiversity Strategy and Action Plan, manage the research application and approval process, organize biodiversity research presentations and workshops and to regularly review the kind of biodiversity research being conducted in Singapore.

Requirements

  • Degree from a recognized university and at least 3 years of work experience
  • Have at minimum a first degree in a relevant discipline
  • Keen interest and passion in biodiversity conservation
  • Strong organization and analytical skills
  • Good writing and interpersonal / communication skills
  • Competence in database management and experience in using Global Information Systems (GIS) will be an advantage
  • Some experience in doing scientific research work

Only shortlisted candidates will be notified.

See also other jobs at the NParks webpage.