sadasd

1. Genomic Tools for improvement of
Nile Tilapia for African Aquaculture
Agustin Barria, Carolina Penaloza, Diego Robledo, Pam Wiener, Andrea
Doeschl-Wilson, Trong Quoc Trinh, Mahirah Mahmuddin, Mohan Chadag,
John Benzie, Ross Houston

2. Nile Tilapia Aquaculture
• Nile tilapia arguably world’s most important food fish
• 4.2 M tonnes per annum produced globally
• Major aquaculture species in SE Asia and Africa
• Selective breeding has major potential to improve production
• GIFT strain developed by WorldFish was a major success
• But to date only focussed on fast growth rate
Target countries for WorldFish

3. Roslin – WorldFish Partnership
• Strategic partnership began in 2018, underpinned by a project
funded by CGIAR to develop genomic selection to improve
disease resistance in Nile tilapia
• Aims:
 To develop a Nile tilapia SNP array with broad utility
 To investigate the genetic basis of disease resistance
 To optimise genomic selection in the core WorldFish
breeding programs (Malaysia and Egypt)

4. • Development and testing of an Axiom SNP array with 65K SNPs
• Whole genome resequencing GIFT strain (Malaysia) plus previous
SNP datasets from various populations, including Abbassa
(Egypt) and East African farmed and wild strains.
Nile Tilapia SNP Array
SNP array used to distinguish tilapia
populations of different origin
Number of SNPs segregating in major
breeding program populations

5. • Tilapia Lake Virus (TiLV) is a flu-like virus causing
high mortalities in tilapia farming
• ‘Opportunistic’ sampling from a pond outbreak
(March 2018) in ~1,800 fish of known pedigree
• Estimation of genetic parameters for resistance
Genomics of disease resistance
High heritability of resistance [h2 = 0.58 (0.04)]
Passive Integrated Transponder (PIT) tags
Countries impacted by TiLV outbreaks

6. • Testing and optimising genomic selection for Malaysia and
Egyptian breeding programmes to improve disease resistance
• Population genetic analyses and signatures of selection
• Support breeding program development for local African strains
 Major interest and potential for improving African aquaculture
 Concerns / debate about import of ‘improved’ strains
Future directions