The co-expression of <i>sGnRH3</i> and <i>skissr</i> in the saccus vasculosus during the different gonad stages.

<p>The co-expression in the SV is similar to that in the hypothalamus. A-D: the co-expression pattern of <i>sGnRH3</i> and <i>skissr</i> in fish with gonads at stage II; E-H: The co-expression pattern of <i>sGnRH3</i> and <i>skissr</i> in fish with gonads at stage III/ IV; I-L: The co-expression pattern of <i>sGnRH3</i> and <i>skissr</i> in fish with gonads at stage V.</p

The expression pattern of <i>sGnRH3</i> in the hypothalamus (3a) and saccus vasculosus(3b) during the development of Atlantic salmon.

<p>II: the gonad at stage II; III: the gonad at stage III; IV: the gonad at stage IV; V: the gonad at stage V.</p

The histology of the Atlantic salmon hypothalamus and saccus vasculosus in Atlantic salmon; A: longitudinal section of the Atlantic salmon brain. B: enlarged picture of the hypothalamus; C: enlarged picture of the saccus vasculosus.

<p>Hyp: hypothalamus; SV: saccus vasculosus. Green arrows indicate the coronet cells; the red arrow indicates the supporting cells; and the yellow arrow indicates the cerebrospinal fluid- contacting cells. NH: neurohypophysis.</p

The expression levels of <i>skissr</i> transcripts in the hypothalamus (Fig 4a and 4c) and saccus vasculosus (Fig 4b and 4d) in fish with gonads at stage II (Fig 4a and 4b) and stage V (Fig 4c and 4d) under different photoperiod treatments.

<p>Data are shown as mean ±SD. One-way ANOVA is performed to determine the significant differences between means Columns sharing different letters show significant difference (p < 0.05).</p

The co-expression of <i>sGnRH3</i> and <i>kissr</i> in the hypothalamus during the different stages of gonad development.

<p>A-D: the co-expression pattern of sGnRH3 and <i>skissr</i> in fish with gonad at stage II; E-H: the co-expression pattern of <i>sGnRH3</i> and <i>skissr</i> in fish with gonads at stage III/ IV (at this time, the transcript levels of <i>kissr</i> are very low); I-L: the co-expression pattern of <i>sGnRH3</i> and <i>skissr</i> in fish with gonads at stage V.</p

The primers used for amplification of gene by PCR.

<p>The primers used for amplification of gene by PCR.</p

The expression levels of <i>sGnRH3</i> transcripts in the hypothalamus (Fig 5a and 5c) and saccus vasculosus (Fig 5b and 5d) in fish with gonads at stage II (Fig 5a and 5b) and stage V (Fig 5c and 5d) under the different photoperiod treatments.

<p>Data are shown as mean ±SD. One-way ANOVA is performed to determine the significant differences between means Columns sharing different letters show significant difference (p < 0.05).</p

The primers used for real-time RT-PCR.

<p>The primers used for real-time RT-PCR.</p

The expression pattern of <i>skissr</i> in the hypothalamus (2a) and SV (2b) during the development process of Atlantic salmon.

<p>II: the gonad at stage II; III: the gonad at stage III; IV: the gonad at stage IV; V: the gonad at stage V. Fig 2c: The expression of <i>kissr</i> in the Atlantic salmon hypothalamus (A, B, C) and SV (D, E, F) when fish with different stages of gonad development are assayed using <i>in situ</i> hybridization. SV: Saccus vasculosus. The <i>kissr</i> was mainly expressed in the early and late stages of gonad development in Atlantic salmon both in the hypothalamus and the SV. Data are shown as mean ±SD. One-way ANOVA is performed to determine the significant differences between means Columns sharing different letters show significant difference (p < 0.05).</p

Photoperiod regulate gonad development via kisspeptin/kissr in hypothalamus and saccus vasculosus of Atlantic salmon (<i>Salmo salar</i>) - Fig 1

<p>1a: The distribution of <i>sGnRH3</i> and <i>skissr</i> in the Atlantic salmon brain. Tel: telencephalon; Dien: diencephalon; Mes: mesencephalon; Pit: pituitary gland; SV: saccus vasculosus. Fig 1b: The expression of <i>sGnRH3</i> and <i>skissr</i> in the hypothalamus (A, B) and SV (C, D). The cells which express <i>sGnRH3</i> mRNA are indicated by blue arrows; the white arrows indicate the supporting cells of the SV; and the yellow arrows indicate the coronet cells of the SV. The results show that <i>skissr</i> is mainly expressed in the cerebrospinal fluid-contacting (CSF-c) cells of the SV. Hyp: hypothalamus; SV: saccus vasculosus; Results are presented as mean ± SD. Significant differences were found at p≦0.5* and p≦0.1**; and different letters indicate statistical significance at p < 0.05.</p