Toward a More Comprehensive View of α-Amylase across Decapods Crustaceans

Abstract

Decapod crustaceans are a very diverse group and have evolved to suit a wide variety of diets. Alpha-amylases enzymes, responsible for starch and glycogen digestion, have been more thoroughly studied in herbivore and omnivore than in carnivorous species. We used information on the α-amylase of a carnivorous lobster as a connecting thread to provide a more comprehensive view of α-amylases across decapods crustaceans. Omnivorous crustaceans such as shrimps, crabs, and crayfish present relatively high amylase activity with respect to carnivorous crustaceans. Yet, contradictory results have been obtained and relatively high activity in some carnivores has been suggested to be a remnant trait from ancestor species. Here, we provided information sustaining that high enzyme sequence and overall architecture conservation do not allow high changes in activity, and that differences among species may be more related to number of genes and isoforms, as well as transcriptional and secretion regulation. However, recent evolutionary analyses revealed that positive selection might have also occurred among distant lineages with feeding habits as a selection force. Some biochemical features of decapod α-amylases can be related with habitat or gut conditions, while less clear patterns are observed for other enzyme properties. Likewise, while molt cycle variations in α-amylase activity are rather similar among species, clear relationships between activity and diet shifts through development cannot be always observed. Regarding the adaptation of α-amylase to diet, juveniles seem to exhibit more flexibility than larvae, and it has been described variation in α-amylase activity or number of isoforms due to the source of carbohydrate and its level in diets, especially in omnivore species. In the carnivorous lobster, however, no influence of the type of carbohydrate could be observed. Moreover, lobsters were not able to fine-regulate α-amylase gene expression in spite of large changes in carbohydrate content of diet, while retaining some capacity to adapt α-amylase activity to very low carbohydrate content in the diets. In this review, we raised arguments for the need of more studies on the α-amylases of less studied decapods groups, including carnivorous species which rely more on dietary protein and lipids, to broaden our view of α-amylase in decapods crustaceans.

Transcriptomic Insights and the Development of Microsatellite Markers to Assess Genetic Diversity in the Broodstock Management of Litopenaeus stylirostris

“…Therefore, effective genetic management is crucial to safeguard the health and adaptability of aquaculture populations. When genes associated with immunity [ 84 , 85 ], reproduction [ 86 , 87 ], environmental stress response [ 68 , 88 , 89 , 90 ], behavior [ 91 ], and other functions experience a loss of diversity, the population’s capacity to adapt is compromised, thereby heightening the risk of encountering various ecological pressures. The analysis of functional markers corresponds to key functional genes associated with resistance traits against White Spot Syndrome Virus (WSSV) and Acute Hepatopancreatic Necrosis Disease (AHPND) found in the transcriptome sequencing dataset.…”

Digestive enzymes of postweaned greenlip abalone (Haliotis laevigata) are influenced by water temperatures and dietary protein levels

“…Carbohydrates of various sources are essential in abalone diets and are typically included in feed at well over 20% inclusion. The dietary carbohydrates are hydrolysed primarily by α‐amylase in the digestive tract and thus should meet the demand for energetic requirements of abalone (Dunstan et al., 2000; Rodríguez‐Viera et al., 2021). Among the carbohydrases, α‐amylase activity is known to be positively correlated to dietary carbohydrate intake in many species (Rodríguez‐Viera et al., 2021).…”

“…The dietary carbohydrates are hydrolysed primarily by α-amylase in the digestive tract and thus should meet the demand for energetic requirements of abalone (Dunstan et al, 2000;Rodríguez-Viera et al, 2021). Among the carbohydrases, α-amylase activity is known to be positively correlated to dietary carbohydrate intake in many species (Rodríguez-Viera et al, 2021). In the current study, α-amylase activity of abalone at 20 y, z: for variables with a significant effect of protein level and no interaction, values without a common lower-case letter are significantly different (z indicates the highest value; p < 0.05).…”

“…Digestive enzyme activity of abalone, as in other species, is significantly influenced by diet (Bansemer et al., 2016; Erasmus et al., 1997; García‐Carreño et al., 2003; Garcia‐Esquivel & Felbeck, 2006; Knauer et al., 1996) and potentially thermal stress (Frederick et al., 2022). The natural diet of abalone consists of macroalgae; therefore, they possess various enzymes capable of breaking down the cell walls of carbohydrates, such as amylases that specifically hydrolyse starch and glycogen (Fleming et al., 1996; Rodríguez‐Viera et al., 2021). Proteases, often reported as trypsin and chymotrypsin activity, are found in the digestive system of many vertebrate and invertebrate organisms, where they are responsible for the breakdown of amino acids.…”

“…The natural diet of abalone consists of macroalgae; therefore, they possess various enzymes capable of breaking down the cell walls of carbohydrates, such as amylases that specifically hydrolyse starch and glycogen (Fleming et al, 1996;Rodríguez-Viera et al, 2021). Proteases, often reported as trypsin and chymotrypsin activity, are found in the digestive system of many vertebrate and invertebrate organisms, where they are responsible for the breakdown of amino acids.…”