Gene:  Insulin-like Growth Factor I (IGF-I)
Taxa:  Oncorhynchus kisutch (Coho Salmon)
 

Gene Function       Gene Sequence       References

Gene Function

IGF-1 is important for growth regulation in fish.  Increased levels of IGF-1 increase both carbohydrate metabolism and lipolysis while simultaneously enhancing synthesis of muscle protein (Mommsen 1998).  IGF-I may affect fish behavior by increasing aggressiveness and food consumption (Mommsen 1998).  IGF-I is particularly important in early developmental stages (Mommsen 1998).  However, at later life-history stages, IGF-1 may be upregulated in liver and gill tissues (Mommsen 1998) and may serve as an indicator of smoltification in salmon (Beckman and Dickhoff 1998).  Ilevated levels of IGF-I have been measured in early maturing fish (Shearer and Swanson 2000) but this may be an indicator of rapid growth rather than a predictor of sexual development (Silverstein et al. 1998).  IGF-I also plays a role in gonadal development and, along with insulin and other hormones, increases cell division during vitellogenesis (Van der Kraak et al. 1998).  Apoptosis is suppressed in ovarian follicles by IGF-I although the role this hormone plays in controlling cell death may change during different stages of ovarian development (Van der Kraak et al. 1998).
References

Gene Sequence
IGF-1 in O. kisutch:

exon 1 and promotor region:  NCBI Accession Number AH007362 or S74130
(FASTA format)

>gi|1683371|gb|AH007362.1| IGF-I=insulin-like growth factor I {exon 1, promoter} [Oncorhynchus kisutch=coho salmon, Genomic, 912 nt 2 segments]
TGTATGAAAAAAGAGACCAATGCCAGGCTACCTGCTGACTGTGTGTGCACTGTACTAAACACTCAAATAT
TCTAGTTTATGAAAATATTTAAATCATGATGATGAATAAGCCCACTAAATCAAACGTTGGAGATAGATAG
ATATGTATGCAATAGATGATGAATACGCAGTTGGAGATAGATATGTATGCAATAGATGAATACGCAGACA
CATAGCCTACATGTGGCACATAAATTACGCCGAGCTTCGTGGACAATAATTATATTATTCCAATGCCTAT
AACAACTCATCATTGAGATTTCTACACGTAACAAGCTTTGAGAAGAGCGGGTGGTAGTGGGTCCAAGCCT
TAAAGAGATCCAAATTCAATCCCATTCTAAGAAAAGTATAAATGATGACGTTATTTGAATATGTGCCCAA
AATCCTTAATGAATAATTTAGGATGAGGAGAAGGCAAATGCTGCCCCAGCTGTTTCCTGTTGAAAATGTC
TGTGTAATGTAGATACATGTGAGGGATTTTCTCTCTAAATCCGTCTCCAGTTCGCTAAATCTCACTTCTC
CAAAACGAGCCTGCGCAATGGAACAAAGTCGGAATATTGAGATGTGACATTGCCTGCATCTTATCCACTT
TCTCACTGTTTTTAATGACTTCAAACAAGTTCATTTTTGCTGGGGCTTTGTCGGTGCGGAGACCCGTGGG
ATGTCTAGCGGTCATTTCTTCCAGTGGCATTTATGTGATGTCTTCAAGGTAGAGTGCGATCTGCTGTGTC
TCCTGTACCCACACCCTCTCACTGCTGCTGTGCGTCCTAACCCTGACTTCGGCGGCAACAGGGGCGGGGC
CCGAGACCCTGTGTGGGGCGGAGCTGGTGGACACGCTGCAGTTTGTGTGTGGAGAGAGAGGCTTTTATTT
CA

and a second segment

NCBI Accession Number S74132
>gi|707009|gb|S74132.1|S74130S2 IGF-I=insulin-like growth factor I {exon 1, promoter} [Oncorhynchus kisutch=coho salmon, Genomic, 162 nt, segment 2 of 2]
AGAGTGCGATCTGCTGTGTCTCCTGTACCCACACCCTCTCACTGCTGCTGTGCGTCCTAACCCTGACTTC
GGCGGCAACAGGGGCGGGGCCCGAGACCCTGTGTGGGGCGGAGCTGGTGGACACGCTGCAGTTTGTGTGT
GGAGAGAGAGGCTTTTATTTCA


NCBI Accession Numbers for related genes in O. kistuch:
IGF-I precurser:  M81911,  M81913
IGF-I receptor:  AF062500, AF062499, AF021045, AF021044, AF021043, AF021042, AF021041, AF021040
SNPS in IGF-1:  DQ274156


NCBI Accession Numbers for IGF-I in related taxa:
O. keta:            X97225, AH004580, S70778, S70777
O. nerka:          DQ025690
O. tshawytscha: U15962,U15961,U15960,U14536
O. mykiss:         M95183

More information on IGF-I in O. mykiss (rainbow trout) is also available here
Protein Sequence

GenBank Accession Number: AAD14148
(FASTA format)
>gi|4261848|gb|AAD14148.1|1683371_1 insulin-like growth factor I [Oncorhynchus kisutch]
MSSGHFFQWHLCDVFK

EST Matches
Results of BLAST search for similar EST sequences:  


Sequences producing significant alignments:
(Click headers to sort columns)




Accession
Description
Max score
Total score
Query coverage
E value
Max ident
Links







EB503182.1
  lmos2p02e11_SP6 Striped sea bream hepatic library Lithognathus mormyrus cDNA, mRNA sequence
 584 58446%2e-16391%


EB503183.1
  lmos2p02e11_T7 Striped sea bream hepatic library Lithognathus mormyrus cDNA, mRNA sequence
 580 58046%3e-16291%


EH499071.1
  FDR107-P00043-DEPE-F_F23 FDR107 Danio rerio cDNA clone FDR107-P00043-BR_F23 5', mRNA sequence
 527 52749%4e-14688% UniGene info


EH489979.1
  FDR107-P00018-DEPE-F_L07 FDR107 Danio rerio cDNA clone FDR107-P00018-BR_L07 5', mRNA sequence
 488 48847%2e-13487% UniGene info


DT080649.1
  AGENCOURT_56117253 NIH_ZGC_7 Danio rerio cDNA clone IMAGE:7998031 5', mRNA sequence
 468 46846%2e-12887% UniGene info


CA381456.1
  660964 NCCCWA 1RT Oncorhynchus mykiss cDNA clone 1RT55N12_D_G06 5', mRNA sequence
 394 39425%4e-10697% UniGene info


BF717691.1
  fd50f06.y1 Zebrafish WashU MPIMG EST Danio rerio cDNA clone IMAGE:3733187 5' similar to SW:IGFA_CYPCA Q90325 INSULIN-LIKE GROWTH FACTOR I, ADULT FORM PRECURSOR. ;, mRNA sequence
 333 33340%8e-8883% UniGene info



Results of BLAST search for EST sequences from the GRASP project: 
data from May 2004
                                                                 Score    E
Sequences producing significant alignments:                      (bits) Value

omyk-CA381456                                                     398   e-109 
omyk-CA356079                                                      46   0.005
References

Beckman BR, Dickhoff WW (1998)  Plasticity of smolting in spring chinook salmon:  relation to growth and insulin-like growth factor-I.  Journal of Fish Biology 53, 808-826

Mommsen TP (1998) Growth and metabolism.  In:  The Physiology of Fishes (ed. Evans DH), p. 519.  CRC Press, New York.

Shearer KD, Swanson P (2000)  The effect of whole body lipid on early sexual maturation of 1+ age male chinook salmon (Oncorhynchus tshawytscha).  Aquaculture 190, 343-367.

Silverstein JT, Shearer KD, Dickhoff WW, Pilsetskaya EM (1998) Effects of growth and fatness on sexual development of chinook salmon (Ocorhynchus tshawytscha) parr.  Canadian Journal of Fisheries and Aquatic Science 55, 2376-2382.

Van der Kraak G, Chang JP, Janz DM (1998)  Reproduction. In:  The Physiology of Fishes (ed. Evans DH), P. 519. CRC Press, New York.