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Transciptomic and histological analysis of hepatopancreas, muscle and gill tissues of oriental river prawn (Macrobrachium nipponense) in response to chronic hypoxia.

Sun S, Xuan F, Fu H, Zhu J, Ge X, Gu Z - BMC Genomics (2015)

Bottom Line: Oriental river prawn, Macrobrachium nipponense, is a commercially important species found in brackish and fresh waters throughout China.However, the effects of dissolved oxygen availability on gene expression and physiological functions of those tissues of prawns are unknown.Genes from well known functional categories and signaling pathways associated with stress responses and adaptation to extreme environments were significantly enriched, including genes in the functional categories "response to stimulus", "transferase activity" and "oxidoreductase activity", and the signaling pathways "oxidative phosphorylation", "glycolysis/gluconeogenesis" and "MAPK signaling".

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, 214081, People's Republic of China. sunshengming621416@163.com.

ABSTRACT

Background: Oriental river prawn, Macrobrachium nipponense, is a commercially important species found in brackish and fresh waters throughout China. Chronic hypoxia is a major physiological challenge for prawns in culture, and the hepatopancreas, muscle and gill tissues play important roles in adaptive processes. However, the effects of dissolved oxygen availability on gene expression and physiological functions of those tissues of prawns are unknown. Adaptation to hypoxia is a complex process, to help us understand stress-sensing mechanism and ultimately permit selection for hypoxia- tolerant prawns, we performed transcriptomic analysis of juvenile M. nipponense hepatopancreas, gill and muscle tissues by RNA-Seq.

Results: Approximately 46,472,741; 52,773,612 and 58,195,908 raw sequence reads were generated from hepatopancreas, muscle and gill tissues, respectively. A total of 62,722 unigenes were generated, of the assembled unigenes, we identified 8,892 genes that were significantly up-regulated, while 5,760 genes were significantly down-regulated in response to chronic hypoxia. Genes from well known functional categories and signaling pathways associated with stress responses and adaptation to extreme environments were significantly enriched, including genes in the functional categories "response to stimulus", "transferase activity" and "oxidoreductase activity", and the signaling pathways "oxidative phosphorylation", "glycolysis/gluconeogenesis" and "MAPK signaling". The expression patterns of 18 DEGs involved in hypoxic regulation of M. nipponense were validated by quantitative real-time reverse-transcriptase polymerase chain reactions (qRT-PCR; average correlation coefficient = 0.94). In addition, the hepatopancreas and gills exhibited histological differences between hypoxia and normoxia groups. These structural alterations could affect the vital physiological functions of prawns in response to chronic hypoxia, which could adversely affect growth and survival of M. nipponense.

Conclusions: Gene expression changes in tissues from the oriental river prawn provide a preliminary basis to better understand the molecular responses of M. nipponense to chronic hypoxia. The differentially expressed genes (DEGs) identified in M. nipponense under hypoxia stress may be important for future genetic improvement of cultivated prawns or other crustaceans through transgenic approaches aimed at increasing hypoxia tolerance.

No MeSH data available.


Related in: MedlinePlus

Venn diagram of DEGs among three tissues from Macrobrachium nipponense
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Fig4: Venn diagram of DEGs among three tissues from Macrobrachium nipponense

Mentions: We detected 13,466 DEGs between hypoxia and normoxia conditions in the hepatopancreas, muscle and gill tissues (false discovery rate ≤0.01 and fold-change ≥2; Fig. 2). Scatter plots were generated for FPKM values from the two treatment groups (Fig. 3). Of these DEGs, 4153, 1985 and 8814 genes were expressed in response to normoxia in hepatopancreas, muscle and gill tissues respectively (Additional file 1A-C). A Venn diagram of the DEGs illustrates that the majority of these genes were not shared amongst the three tissue types, suggesting that the mechanisms and pathways employed in response to chronic hypoxia stress differ significantly between hepatopancreas, gill and muscle tissues (Fig. 4). A key regulator of cellular adaptations to hypoxia is the transcriptional activator hypoxia inducible factor 1 (HIF-1) [30]; however, in our present study with M. nipponense – and in previous studies on other invertebrates –HIF-1α mRNA levels in the hepatopancreas consistently showed no response to hypoxia or anoxia [20, 31–34]. The results suggest a model of hypoxia-induced regulation of HIF-1α transcript abundance in crustaceans that may differs from that of typical HIF-1α transcriptional regulation in mammalian systems. Since HIF exerts its action at the level of protein and not mRNA expression level, the absence of HIF among the DEG is not surprising.Fig. 2


Transciptomic and histological analysis of hepatopancreas, muscle and gill tissues of oriental river prawn (Macrobrachium nipponense) in response to chronic hypoxia.

Sun S, Xuan F, Fu H, Zhu J, Ge X, Gu Z - BMC Genomics (2015)

Venn diagram of DEGs among three tissues from Macrobrachium nipponense
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4490754&req=5

Fig4: Venn diagram of DEGs among three tissues from Macrobrachium nipponense
Mentions: We detected 13,466 DEGs between hypoxia and normoxia conditions in the hepatopancreas, muscle and gill tissues (false discovery rate ≤0.01 and fold-change ≥2; Fig. 2). Scatter plots were generated for FPKM values from the two treatment groups (Fig. 3). Of these DEGs, 4153, 1985 and 8814 genes were expressed in response to normoxia in hepatopancreas, muscle and gill tissues respectively (Additional file 1A-C). A Venn diagram of the DEGs illustrates that the majority of these genes were not shared amongst the three tissue types, suggesting that the mechanisms and pathways employed in response to chronic hypoxia stress differ significantly between hepatopancreas, gill and muscle tissues (Fig. 4). A key regulator of cellular adaptations to hypoxia is the transcriptional activator hypoxia inducible factor 1 (HIF-1) [30]; however, in our present study with M. nipponense – and in previous studies on other invertebrates –HIF-1α mRNA levels in the hepatopancreas consistently showed no response to hypoxia or anoxia [20, 31–34]. The results suggest a model of hypoxia-induced regulation of HIF-1α transcript abundance in crustaceans that may differs from that of typical HIF-1α transcriptional regulation in mammalian systems. Since HIF exerts its action at the level of protein and not mRNA expression level, the absence of HIF among the DEG is not surprising.Fig. 2

Bottom Line: Oriental river prawn, Macrobrachium nipponense, is a commercially important species found in brackish and fresh waters throughout China.However, the effects of dissolved oxygen availability on gene expression and physiological functions of those tissues of prawns are unknown.Genes from well known functional categories and signaling pathways associated with stress responses and adaptation to extreme environments were significantly enriched, including genes in the functional categories "response to stimulus", "transferase activity" and "oxidoreductase activity", and the signaling pathways "oxidative phosphorylation", "glycolysis/gluconeogenesis" and "MAPK signaling".

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, 214081, People's Republic of China. sunshengming621416@163.com.

ABSTRACT

Background: Oriental river prawn, Macrobrachium nipponense, is a commercially important species found in brackish and fresh waters throughout China. Chronic hypoxia is a major physiological challenge for prawns in culture, and the hepatopancreas, muscle and gill tissues play important roles in adaptive processes. However, the effects of dissolved oxygen availability on gene expression and physiological functions of those tissues of prawns are unknown. Adaptation to hypoxia is a complex process, to help us understand stress-sensing mechanism and ultimately permit selection for hypoxia- tolerant prawns, we performed transcriptomic analysis of juvenile M. nipponense hepatopancreas, gill and muscle tissues by RNA-Seq.

Results: Approximately 46,472,741; 52,773,612 and 58,195,908 raw sequence reads were generated from hepatopancreas, muscle and gill tissues, respectively. A total of 62,722 unigenes were generated, of the assembled unigenes, we identified 8,892 genes that were significantly up-regulated, while 5,760 genes were significantly down-regulated in response to chronic hypoxia. Genes from well known functional categories and signaling pathways associated with stress responses and adaptation to extreme environments were significantly enriched, including genes in the functional categories "response to stimulus", "transferase activity" and "oxidoreductase activity", and the signaling pathways "oxidative phosphorylation", "glycolysis/gluconeogenesis" and "MAPK signaling". The expression patterns of 18 DEGs involved in hypoxic regulation of M. nipponense were validated by quantitative real-time reverse-transcriptase polymerase chain reactions (qRT-PCR; average correlation coefficient = 0.94). In addition, the hepatopancreas and gills exhibited histological differences between hypoxia and normoxia groups. These structural alterations could affect the vital physiological functions of prawns in response to chronic hypoxia, which could adversely affect growth and survival of M. nipponense.

Conclusions: Gene expression changes in tissues from the oriental river prawn provide a preliminary basis to better understand the molecular responses of M. nipponense to chronic hypoxia. The differentially expressed genes (DEGs) identified in M. nipponense under hypoxia stress may be important for future genetic improvement of cultivated prawns or other crustaceans through transgenic approaches aimed at increasing hypoxia tolerance.

No MeSH data available.


Related in: MedlinePlus