Identification and genetic mapping of RAPD markers linked to the densonucleosis refractoriness gene, nsd-2, in the silkworm, Bombyx mori.
In the silkworm, Bombyx mori, nonsusceptibility to B. mori densonucleosis virus type-2 (BmDNV-2) is controlled by a recessive gene, nsd-2 (nonsusceptibility to DNV-2). We investigated the genetic linkage between two random-amplified polymorphic DNA (RAPD) markers and the +nsd-2 gene. Initially, we constructed the JSD-2 strain (nsd-2/+), which is congenic to strain J137 (nsd-2/nsd-2) with respect to the chromosome containing the +nsd-2 gene, starting with a female of strain J137 and a male of strain C137 (+nsd-2/+nsd-2). Genomic DNAs were compared between infected individuals of the JSD-2 strain and J137 by a polymerase chain reaction (PCR) with 700 arbitrary 10-mer primers. Two RAPD markers (OPH19R and OPP01R) linked to the +nsd-2 gene were found. For the crossing-over experiment, a female of J137 was crossed with a male (nsd-2/+) of JSD-2. Segregation analysis showed that the most closely linked RAPD marker (OPP01R) was mapped 4.7 cM distant from +nsd-2.
Abe
H
H
Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan. wfem@cc.tuat.ac.jp
Sugasaki
T
T
Kanehara
M
M
Shimada
T
T
Gomi
S J
SJ
Ohbayashi
F
F
Oshiki
T
T
D000818:Animals; D012831:Bombyx / Q000235:genetics*; D002874:Chromosome Mapping; D017990:Densovirus / Q000235:genetics; D007113:Immunity, Innate / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique