Paternity assignment in the polyploid Acipenser dabryanus based on a novel microsatellite marker system

Area of Science:

• Conservation genetics
• Aquaculture
• Ichthyology

Background:

• Dabry's sturgeon (Acipenser dabryanus) is critically endangered, necessitating effective ex situ conservation strategies.
• Successful captive breeding programs require knowledge of genetic diversity and relatedness among individuals.
• Existing genetic markers may be insufficient for detailed population studies in this species.

Purpose of the Study:

• To develop novel and reliable microsatellite markers for genetic studies of Acipenser dabryanus.
• To assess the genetic diversity and reproductive patterns within a captive breeding population.
• To evaluate the efficiency of developed markers in parentage assignment for conservation management.

Main Methods:

• Transcriptome sequencing was employed to identify simple sequence repeats (SSRs).
• 100 microsatellite loci were screened, and 20 polymorphic, non-dinucleotide markers with good repeatability were selected.
• Parentage assignment analysis was conducted using 43 captive broodstock (F1) and 96 offspring (F2), alongside mitochondrial DNA analysis.

Main Results:

• A total of 14,321 SSRs were detected, leading to the selection of 20 novel polymorphic microsatellites.
• The developed SSRs achieved a 91.7% parentage allocation success rate in the captive population.
• Analysis indicated limited family contribution to progeny and a high probability of shared lineage among captive broodstock, suggesting potential inbreeding.

Conclusions:

• The 20 newly developed microsatellite markers are effective for genetic and paternity studies in Acipenser dabryanus.
• The findings highlight potential inbreeding issues within the current captive breeding stock.
• These markers can be utilized in future breeding programs to manage genetic diversity and avoid inbreeding in Acipenseriformes species.