Genetic Variability Assessed by Microsatellites in a Breeding Program of Pacific White Shrimp (Litopenaeus vannamei)

P. Cruz, A.M. Ibarra, H. Mejia-Ruiz, P.M. Gaffney, R. Pérez-Enríquez-2004

Marine Biotechnology, 6(2): 157-164

Abstract:

Genetic diversity in a shrimp-breeding program was monitored for 2 generations by microsatellite DNA markers (Pvan1578 and Pvan1815) to establish levels of variation and proceed with a selection program. An increase in the number and frequencies of some alleles in both microsatellite loci from G₀ to G₂ was induced by foreign sire contributions. Most common alleles and high heterozygosities (around 70% in both loci) were maintained through the generations, indicating that there had not been a significant loss of genetic variability in the breeding program. However, when compared with variability in other wild and cultured stocks, the presence of 4 main alleles at both loci may be an indication that a certain reduction in variability already was present in the line used as founder stock (G₀). Therefore, it is recommended that additional genetic variability be introduced to the breeding stock by crossing it with a different line.

(Laboratorio de Genética Acuícola, Centro de Investigaciones Biológicas del Noroeste (CIBNOR) A.P. 128, La Paz, Baja California Sur 23000, México, e-mail of R. Perez-Enriquez: rperez@cibnor.mx)

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