3.5 Fish Gene Structures
This section introduces the fish genes for globin, hormones, and transferrin, which
are currently the subject of analysis.
A. Globin Genes
The hemoglobin found in fish blood performs a very important role in respiratory
physiology. Hemoglobin is a conjugated protein formed as two a-globin and two
b-globin chains are joined and each of the four globins combines with a heme.
Table 3.4 Number of genes expressed in the flounder’s leukocytes, liver, and spleen as
determined by EST analysis
Cell function
Leukocytes
Liver
Spleen
Cell division
8
3
1
Intercellular information/signal transmission factors
46
2
0
Cell structure and movement
28
3
2
Cell/organism defense factors
21
8
2
Gene/protein expression
83
27
7
Energy metabolism
33
9
1
Other
94
34
4
Total
313
86
17
Table 3.3 Number of clones analysed in the leukocytes, liver, and spleen (Nam et al. 2000)
Number of clones analyzed
1374
Leukocytes
983
Liver
350
Spleen
41
Number of ESTs analyzed
1792 base sequences
Leukocytes
1242 ESTs
Liver
493 ESTs
Spleen
57 ESTs
Clones with visible homology
787 (57.3%)
Clones without visible homology
587 (42.7%)
Number of different clones with visible homology
416
Leukocytes
313
Liver
86
Spleen
17
Total number of bases analyzed
1,254,858 base pairs (bp)
Average number of bases set per EST
700 base pairs (bp)
66
3 Fish Genetics