Biotechnology breakthroughs presented

By Development Communication Section

Professor Abigail Elizur, professor of aquaculture biotechnology and director of genecology research center of University Sunshine Coast in Queensland, Australia, presented a seminar on “Biotechnology applications in marine aquaculture” on 20 January at AQD’s Tigbauan Main Station.

Dr. Elizur discussed four major biotechnology applications such as (1) manipulation of finfish reproduction, (2) surrogate technology in finfish, (3) monosex technology in prawns and (4) spawning inducing peptides in oysters.

She discussed hormone manipulations to help both finfish (using gonadotropin-releasing hormone or GnRH) and oysters (peptide hormones) to advance pubertal development and induce spawning. As for the study in tuna, successful spawning always happened after delivery of hormones to the animal. It was also discovered that one female dominated the spawning events as assessed using mtDNA and microsatellite DNA and that the females can spawn every day for a period of few weeks and different females spawn at different times of the season. For oysters, spawning was stimulated at the early stages of reproductive development. They are also trying to identify reproductive peptides from transcriptomes and use it to advance reproductive performance.

She also discussed her study on surrogate technology as an alternative broodstock system. Basically, it aims to engineer yellowtail kingfish (YTK) to produce southern Bluefin tuna (SBT). The experiment uses germ cell transplantation wherein SBT germ cells are transplanted in the abdominal cavity of YTK where they migrate to the immature gonads of the host. However, no proliferation of the Bluefin tuna germ cells could be detected in the kingfish. Dr. Elizur and her team are now planning to study surrogate technology on giant grouper.

Dr. Elizur discussed creating monosex populations in crustaceans using androgenic gland manipulations specifically in Penaeus monodon. All female shrimps can deliver 10-20 times faster in growth and bigger in size and have better feed conversion ratio. The process includes removal of the androgenic gland (a male specific gland which regulates masculine development and maintenance) located at the base of the fifth walking leg, will cause males to become females.