Biology Reference
In-Depth Information
O. latipes
, respectively. It shows no difference in its expression pattern
in the male and female guppy but very interestingly a clear expression
in muscle of adult males but not in that of females (Shen et al., 2007).
Table 10 summarizes the timing and levels of expression of
sox
gene
complex in selected fi sh.
Table 10.
Summary of
sox
gene complex in downstream sex differentiation in fi shes (from
Pandian, 2011, updated)
Species, Reference
Description
Acipenser sturio
Hett et al. (2005)
sox
9 consists of 3 exons and 2 introns with completely
conserved exon-intron boundaries and shows high levels of
homology to
sox9
sequences of other vertebrates, especially in
the N-terminus region containing the HMG box. It reveals no
male or female specifi c difference
A.schrenckii
Chen et al. (2006)
sox
genes express differently in males and females. They code
for transcription factors related to mammalian
Sry
testis-
determining gene
Cyprinus carpio
Du et al. (2007)
sox9a
and
sox9b
differ in having an intron of different lengths
of 704 and 616 bp, respectively in the conserved HMG box
region that codes for identical amino acid sequence. Cc
soxb
overexpresses in adult brain and testis but weakly in ovary
Allotetraploid
Liu et al. (2007)
sox9a
is highly expressed in testis but weakly in brain and heart,
and is not expressed in adult female
3n crucian carp
Guo et al. (2008b)
Isolated and characterized cDNA of
sox9a
, encodes a protein of
457 amino acids with an HMG box.
sox9a
is expressed in testis, as
in zebrafi sh. But the testicular expression of
sox9a
gene 3n seldom
contributes to the formation of functional spermatozoa, although
plays an important role in development of testicular tubules. Thus
the contribution of
sox9
genes differs in different species
Danio rerio
von Hofsten et al.
(2005a,b)
Two
sox
9 genes,
sox9a
and
sox9b
have been identifi ed. Both
contain HMG box and are able to bind the AACAAAG
recognition site.
sox9a
is expressed in testis and
sox9b
in ovary.
FTZ-F1a
(
fushi tarazu
factor-1a) genes are involved in regulation
of inter-renal development and thereby steroid biosynthesis.
sox9a alone does not determine sex but a combination of
sox9a,
FF1a, b, c
and c, MMH GATA and
Dmrt
seems to perform it
Clarias gariepinus
Raghuveer et al. (2011)
Sox9a
is exclusively expressed in male gonads
From a PCR survey of
sox
genes in cyprinid tetraploid tor
To r
douronensis
, Guo et al. (2008b) reported the presence of 13
sox
genes
belonging to
soxB, soxC
and
soxE
groups. Sequence analysis revealed
that most of the nucleotide substitutions between duplicated
copies of
sox
genes were caused by the tetraploidization event or
their orthologues of other species remained silent substitution.
Unexpected variations of the intron length and similarities of the
two duplicated copies of
sox9a
and
sox9b
suggest that
T. douronensis
may be allotetraploid.
