Transcriptomic analysis of the testicular fusion in Spodoptera litura
Background
Lepidoptera is one group of the largest plant-feeding insects and Spodoptera litura (Lepidoptera: Noctuidae) is one of the most serious agricultural pests in Asia countries. An interesting and unique phenomenon for gonad development of Lepidoptera is the testicular fusion. Two separated testes fused into a single one during the larva-to-pupa metamorphosis, which is believed to contribute to sperm production and the prevalence in field. To study the molecular mechanism of the testicular fusion, RNA sequencing (RNA-seq) experiments of the testes from 4-day-old sixth instar larvae (L6D4) (before fusion), 6-day-old sixth instar larvae (L6D6, prepupae) (on fusing) and 4-day-old pupae (P4D) (after fusion) of S. litura were performed.
Results
RNA-seq data of the testes showed that totally 12,339 transcripts were expressed at L6D4, L6D6 and P4D stages. A large number of differentially expressed genes (DEGs) were up-regulated from L6D4 to L6D6, and then more genes were down-regulated from L6D6 to P4D. The DEGs mainly belongs to the genes related to the 20E signal transduction pathway, transcription factors, chitin metabolism related enzymes, the families of cytoskeleton proteins, extracellular matrix (ECM) components, ECM-related protein, its receptor integrins and ECM-remodeling enzymes. The expression levels of these genes that were up-regulated significantly during the testicular fusion were verified by qRT-PCR. The matrix metalloproteinases (MMPs) were found to be the main enzymes related to the ECM degradation and to contribute to the testicular fusion. The testis was not able to fuse if MMPs inhibitor GM6001 was injected into the 5th abdomen region.
Conclusions
The transcriptome and DEGs analysis of the testes at L6D4, L6D6, P4D stages provided genes expression information related to the testicular fusion in S. litura . These results indicated that cytoskeleton proteins, ECM-integrin interaction genes and ECM-related proteins was involved in cell migration, adhesion and fusion during the testicular fusion. The ECM degradation enzymes MMPs probably play a critical role in the fusion of testis.
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Posted 20 Dec, 2019
On 19 Feb, 2020
Received 05 Jan, 2020
Invitations sent on 18 Dec, 2019
On 18 Dec, 2019
On 17 Dec, 2019
On 16 Dec, 2019
On 16 Dec, 2019
On 24 Oct, 2019
Received 23 Oct, 2019
On 14 Oct, 2019
Received 09 Oct, 2019
On 18 Sep, 2019
Invitations sent on 18 Sep, 2019
On 12 Sep, 2019
On 12 Sep, 2019
On 22 Aug, 2019
On 21 Aug, 2019
Transcriptomic analysis of the testicular fusion in Spodoptera litura
Posted 20 Dec, 2019
On 19 Feb, 2020
Received 05 Jan, 2020
Invitations sent on 18 Dec, 2019
On 18 Dec, 2019
On 17 Dec, 2019
On 16 Dec, 2019
On 16 Dec, 2019
On 24 Oct, 2019
Received 23 Oct, 2019
On 14 Oct, 2019
Received 09 Oct, 2019
On 18 Sep, 2019
Invitations sent on 18 Sep, 2019
On 12 Sep, 2019
On 12 Sep, 2019
On 22 Aug, 2019
On 21 Aug, 2019
Background
Lepidoptera is one group of the largest plant-feeding insects and Spodoptera litura (Lepidoptera: Noctuidae) is one of the most serious agricultural pests in Asia countries. An interesting and unique phenomenon for gonad development of Lepidoptera is the testicular fusion. Two separated testes fused into a single one during the larva-to-pupa metamorphosis, which is believed to contribute to sperm production and the prevalence in field. To study the molecular mechanism of the testicular fusion, RNA sequencing (RNA-seq) experiments of the testes from 4-day-old sixth instar larvae (L6D4) (before fusion), 6-day-old sixth instar larvae (L6D6, prepupae) (on fusing) and 4-day-old pupae (P4D) (after fusion) of S. litura were performed.
Results
RNA-seq data of the testes showed that totally 12,339 transcripts were expressed at L6D4, L6D6 and P4D stages. A large number of differentially expressed genes (DEGs) were up-regulated from L6D4 to L6D6, and then more genes were down-regulated from L6D6 to P4D. The DEGs mainly belongs to the genes related to the 20E signal transduction pathway, transcription factors, chitin metabolism related enzymes, the families of cytoskeleton proteins, extracellular matrix (ECM) components, ECM-related protein, its receptor integrins and ECM-remodeling enzymes. The expression levels of these genes that were up-regulated significantly during the testicular fusion were verified by qRT-PCR. The matrix metalloproteinases (MMPs) were found to be the main enzymes related to the ECM degradation and to contribute to the testicular fusion. The testis was not able to fuse if MMPs inhibitor GM6001 was injected into the 5th abdomen region.
Conclusions
The transcriptome and DEGs analysis of the testes at L6D4, L6D6, P4D stages provided genes expression information related to the testicular fusion in S. litura . These results indicated that cytoskeleton proteins, ECM-integrin interaction genes and ECM-related proteins was involved in cell migration, adhesion and fusion during the testicular fusion. The ECM degradation enzymes MMPs probably play a critical role in the fusion of testis.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12