PMID- 18511881
OWN - NLM
STAT- MEDLINE
DCOM- 20090716
LR  - 20240308
IS  - 1016-8478 (Print)
IS  - 1016-8478 (Linking)
VI  - 25
IP  - 4
DP  - 2008 Jun 30
TI  - Association of A/T rich microsatellites with responses to artificial selection 
      for larval developmental duration in the silkworm Bombyx mori.
PG  - 467-78
AB  - Simple sequence repeats (SSRs) and interSSR (ISSR) marker systems were used in 
      this study to reveal genetic changes induced by artificial selection for 
      short/long larval duration in the tropical strain Nistari of the silkworm Bombyx 
      mori. Artificial selection separated longer larval duration (LLD) (29.428 (+/-) 
      0.723 days) and shorter larval duration (SLD) (22.573 (+/-) 0.839 days) lines 
      from a base, inbred population of Nistari (larval span of 23.143 (+/-) 0.35 
      days). SSR polymorphism was observed between the LLD and SLD lines at one 
      microsatellite locus, Bmsat106 (CA7) and at two loci of 1074 bp and 823 bp 
      generated with the ISSR primer UBC873. Each of these loci was present only in the 
      LLD line. The loci segregated in the third generation of selection and were fixed 
      in opposite directions. In the F2 generation of the LLD x SLD lines, the alleles 
      of Bmsat106 and UBC8731074bp segregated in a 1:1 ratio and the loci were present 
      only in the LLD individuals. UBC873823bp was homozygous. Single factor ANOVA 
      showed a significant association between the segregating loci and longer larval 
      duration. Together, the two alleles contributed to an 18% increase in larval 
      duration. The nucleotide sequences of the UBC8731074bp and UBC873823bp loci had 
      67% A/T content and consisted of direct, reverse, complementary and palindromic 
      repeats. The repeats appeared to be "nested" (59%) in larger repeats or as 
      clustered elements adjacent to other repeats. Of 203 microsatellites identified, 
      dinucleotides (67.8%) predominated and were rich in A/T and T/A motifs. The 
      sequences of the UBC8731074bp and UBC873823bp loci showed similarity (E = 0.0) to 
      contigs located in Scaffold 010774 and Scaffold 000139, respectively, of the B. 
      mori genome. BLASTN analysis of the UBC8731074bp sequence showed significant 
      homology of (nt.) 45-122 with upstream region of three exons from Bombyx. The 
      complete sequence of this locus showed approximately 49% nucleotide conservation 
      with transposon 412 of Drosophila melanogaster and the Ikirara insertions of 
      Anopheles gambiae. The A + T richness and lack of coding potential of these small 
      loci, and their absence in the SLD line, reflect the active process of genetic 
      change associated with the switch to short larval duration as an adaptation to 
      the tropics.
FAU - Pradeep, Appukuttan Retnabhavan
AU  - Pradeep AR
AD  - Seribiotech Research Laboratory, Carmelram. P.O. Kodathi, Bangalore 560035, 
      Karnataka, India. arpradeep23@rediffmail.com
FAU - Awasthi, Arvind Kumar
AU  - Awasthi AK
FAU - Urs, Raje Siddaraje
AU  - Urs RS
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080529
PL  - United States
TA  - Mol Cells
JT  - Molecules and cells
JID - 9610936
SB  - IM
MH  - AT Rich Sequence/*genetics
MH  - Animals
MH  - *Bombyx/genetics/growth & development
MH  - Cloning, Molecular
MH  - Genes, Insect
MH  - Larva/*genetics/*growth & development
MH  - Microsatellite Repeats/*genetics
MH  - Minisatellite Repeats/genetics
MH  - Polymorphism, Genetic
MH  - Selection, Genetic
MH  - Sequence Alignment
MH  - Sequence Homology, Amino Acid
EDAT- 2008/05/31 09:00
MHDA- 2009/07/17 09:00
CRDT- 2008/05/31 09:00
PHST- 2008/05/31 09:00 [pubmed]
PHST- 2009/07/17 09:00 [medline]
PHST- 2008/05/31 09:00 [entrez]
AID - S1016-8478(23)17607-2 [pii]
PST - ppublish
SO  - Mol Cells. 2008 Jun 30;25(4):467-78. Epub 2008 May 29.