Immunolocalization and expression of Na+/K+ -ATPase in embryos, early larval stages and adults of the freshwater shrimp Palaemonetes argentinus (Decapoda, Caridea, Palaemonidae)

Abstract

The euryhaline shrimp Palaemonetes argentinus exemplifies an evolutionary transition from brackish to freshwater habitats that requires adequate osmoregulatory capacities. Hyperosmoregulation is functional at hatching and it likely begins during the embryonic phase allowing this species to develop entirely in fresh water. Here, we investigated the Na(+)/K(+)-ATPase α-subunit gene (nka-α) expression using quantitative real-time PCR and localized Na(+)/K(+)-ATPase (NKA) in ion-transporting epithelia through immunofluorescence microscopy. We reared shrimps from spawning to juvenile stages at two salinities (1, 15 ‰) and maintained adults for 3 weeks at three salinity treatments (1, 15, 25 ‰). nka-α gene expression was measured in: (1) embryos at an early (SI), intermediate (SII) and late (SIII) stage of embryonic development; (2) newly hatched larvae (Zoea I, ZI); and (3) isolated gill tissue of adults. The nka-α expression was low in SI and SII embryos and reached maximum levels prior to hatching (SIII), which were similar to expression levels detected in the ZI. The nka-α expression in SIII and ZI was highest at 15 ‰, whereas salinity did not affect expression in earlier embryos. In SIII, in ZI and in a later zoeal stage ZIV, NKA was localized in epithelial cells of pleurae, in the inner-side epithelium of branchiostegite and in the antennal glands. Gills appeared in the ZIV but NKA immunolabeling of the cells of the gill shaft occurred in a subsequent developmental larval stage, the decapodid. Extrabranchial organs constitute the main site of osmoregulation in early ontogenetic stages of this freshwater shrimp.

An atlas of larval organogenesis in the European shore crab Carcinus maenas L. (Decapoda, Brachyura, Portunidae)

“…the lateral carapace folds that form the branchial chamber, function as additional organs involved in the transport of gases and ions [ 78 ]. In decapod larvae, it has been suggested that the epidermis of the branchiostegites acts as an ion-transporting epithelium [ 43 ], [ 44 ], [ 79 ], [ 45 ]. In our preparations, the epidermis was artificially detached from the cuticle in the region of the branchiostegites (Bst; Figs.…”

“…In brachyuran crabs, the anterior gills mostly accomplish gas exchange, whereas the transport epithelia, responsible for osmoregulation are located in the posterior gills (reviews [ 106 , 107 ]). There is an increasing interest in the ontogeny of the osmoregulatory system in decapod crustaceans and the ecological implications of larval osmotolerance for aspects such as dispersal, population maintenance and invasive potential of a species [ 43 – 45 , 108 , 79 ]. The zoeal stages of C. maenas do not possess functional gills, only gill anlagen that gradually develop and are visible from the Zoea II onwards [ 43 ], [ 77 ].…”

“…Nevertheless, and despite their outstanding role as models in ecological developmental biology, our current knowledge on the internal anatomy of brachyuran larvae is still rather limited, the most important resources being studies on Cancer anthonyi [ 21 ] and Portunus trituberculatus [ 22 ]. Other techniques to analyse anatomical aspects of the larvae of decapod crustaceans include for example semi-thin sectioning of resin embedded specimens [ 23 – 29 ], three-dimensional reconstruction of histological data [ 30 ], transmission electron microscopy [ 26 , 31 – 34 ], DiI labelling combined with confocal laser-scan microscopy [ 35 ], in vivo incubation with mitosis markers [ 36 – 39 ], nuclear labelling with a DNA markers [ 40 ]) and immunohistochemical localization of neuronal antigens [ 41 , 42 ] and ion pumps within transport epithelia [ 43 – 45 ]. Table 1 summarizes studies on the anatomy of developing organ systems, limited to representatives of the Pleocyemata, but including studies that synthesize data on the transition from embryos to larvae.…”

Estudo bioquímico comparativo da (Na+ , K+)-ATPase branquial de Macrobrachium amazonicum (Heller, 1862) habitante de regiões continentais

“…A anidrase carbônica, a calreticulina, diferentes hormônios peptídicos, fatores de transcrição e as enzimas do estresse oxidativo também apresentam um papel crítico nas funções osmorregulatórias das brânquias dos crustáceos (Henry, 1988a, b;Skaggs & Henry, 2002;Thabet et al, 2017;Moshtaghi et al, 2017;2018 Torres, 1999;Belli et al, 2009), a segunda representada pela V(H + )-ATPase, localizada nas membranas apicais das franjas das células pilares (Faleiros et al, 2010). O Na + do meio externo passa para o citosol das células pilares através de canais de Na + apicais, energizado pelo potencial de membrana criado pela extrusão de H + pela V(H + )-ATPase causando hiperpolarização destas células (Onken & Riestenpatt, 1998;Ituarte et al, 2016). Então canais de Na + levam estes íons para as células do septo, graças à baixa concentração de sódio intracelular nessas células causada pela (Na + , K + )-ATPase, que bombeia esses íons para a hemolinfa (Onken & Riestenpatt, 1998;McNamara & Faria, 2012).…”

“…Quando expostos a altas salinidades os camarões palemonídeos hiperregulam, necessitando secretar Na + e Cl - (Péqueux, 1995;McNamara & Faria, 2012). Esta exposição causa alterações na expressão e na atividade da (Na + , K + )-ATPase e V(H + )-ATPase no tecido branquial, sendo estas alterações são espécie-dependente e muitas vezes também tempodependente, porém algumas espécies não apresentam alterações significativas (Mendonça et al, 2007;Belli et al, 2009;Faleiros et al, 2010;Leone et al, 2014;Lucena et al, 2015;Introdução________________________________________________________________43 Maraschi et al, 2015;Ituarte et al, 2016;Freire et al, 2018;Huang et al, 2019).…”