Teleost Nonapeptides, Isotocin and Vasotocin Administration Released the Milt by Abdominal Massage in Male Catfish, Clarias magur

Abstract

In the present work the nonapeptides i.e., isotocin and vasotocin alone or in a combination were tested in C. magur to evaluate their effect on stripping by abdominal massage. Also, we used chitosan-carbon nanotube nanocomposites to conjugate the nonapetides isotocin (abbreviated as COOH-SWCNTCSPeP) and isotocin and vasotocin (COOH-SWCNTCSPePs) with the aim of sustaining the effect for a longer duration. The conjugation of nonapeptides with nanocomposites was confirmed by Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Two experiments were conducted to study the effect of naked (without nanoparticles) and conjugated nonapeptides on the milt release by stripping. Both the experiments consisted of eight treatments which included four naked groups two nanoconjugated groups and two controls. Both naked and nonconjugated formulations were successful in stripping the male catfish. The mRNA expression of selected reproductive genes was analysed to decipher the effect of nanopeptides at the molecular level. Nonapeptide treatment either naked or nanoconjugated, resulted in the upregulation of the transcript level of genes. Histological analysis revealed the concentration of spermatozoa was more in peptide injected groups than in the controls. The synergistic effects of nonapeptides and Ovatide had a positive impact on GSI. Thus, the present formulations were successful in stripping the male catfish to obtain the milt with significant reproductive success. Even though the naked groups perform better but the number of males required to fertilize the eggs in nanoconjuagted groups was smaller making it worth using for the delivery of nonapeptides.

Reproductive roles of the vasopressin/oxytocin neuropeptide family in teleost fishes

“…In male African sharptooth catfish testes slices 30-min incubation with OXT (at 10 IU), but not Oxt, AVP, epinephrine, PGF 2α , LH and pituitary extracts increased milt release ( 156 ). In male walking catfish, nonapeptides and their nanotube composites designed for slower release were tested for their efficacy to promote stripping of milt by abdominal massage ( 157 ). Both naked or nano-conjugated nonapeptides increased strippable milt concentrations without altering reproductive success of fertilized eggs and increased the expression of the steroidogenesis pathway enzymes star , 3bhsd , 17bhsd , cyp17a1a , ands cyp11a1a ( 157 ).…”

“…Regarding parturition in teleosts, nonapeptides have been reported to stimulate premature parturition in the guppy, Poecilia reticulata , an ovoviviparous teleost ( 82 , 158 ). The injection of Avp, Oxt and PGs to guppy, Poecilia reticulata , a live-bearing teleost, induced premature parturition ( 157 ). Both Avp and Oxt stimulated cox2 mRNA expression in guppy ovaries in vitro , which in the case of Avp, but not Oxt, translated into increased PG concentrations ( 82 ).…”

Schiff-Base Chemistry-Coupled Catechol Oxidase-Like Nanozyme Reaction as a Universal Sensing Mode for Ultrasensitive Biosensing

“…The binding energy (BE) at ∼934.48 and ∼954.39 eV of the Cu 2p spectrum in Figure D could be assigned to Cu 2p 3/2 and Cu 2p 1/2 of Cu­(II), respectively. − The peaks at ∼932.47 and ∼952.43 eV could belong to Cu 2p 3/2 of Cu­(I) and Cu 2p 1/2 of Cu­(II), respectively. , The peaks at ∼944.22 and ∼941.68 eV were connected with Cu­(II). , Additionally, the BE at ∼284.78, ∼285.80, and ∼287.97 eV in C 1s spectrum of His could be corresponded to CC/CC, CO, and CN, respectively. − Three peaks at ∼284.66, ∼285.60, and ∼287.46 eV in the C 1s spectrum of CHzyme could be assigned to CC/CC, CO, and CN, respectively (Figure E). − Meanwhile, two peaks at ∼530.67 and ∼531.42 eV in O 1s of His could be attributed to the CO bond and −OH. , Three peaks in O 1s of CHzyme at ∼530.35, ∼531.09, and ∼532.05 eV could be attributed to CuO, CO, and −OH, respectively, demonstrating the successful coordination between Cu and oxygen atoms (Figure F). − To demonstrate the coordination of Cu­(II) and N atoms in His, the N 1s spectrum of CHzyme was further researched (Figure G). Two peaks at ∼400.23 and ∼398.26 eV in N 1s of His could be attributed to amino groups and the CN bond, respectively. , The BE of ∼400.28 and ∼398.39 eV of CHzyme could be assigned to amino groups and the CN bond in His, respectively. , The peak at ∼399.20 eV exhibited the existing Cu–N bonds, confirming the successful coordination between Cu and N atom in CHzyme . Meanwhile, Fourier transform infrared (FT-IR) spectroscopy was used to analyze the chemical bonding structure status of the prepared CHzyme (Figure H).…”

“…Two peaks at ∼400.23 and ∼398.26 eV in N 1s of His could be attributed to amino groups and the C�N bond, respectively. 30,31 The BE of ∼400.28 and ∼398.39 eV of CHzyme could be assigned to amino groups and the C�N bond in His, respectively. 32,33 The peak at ∼399.20 eV exhibited the existing Cu−N bonds, confirming the successful coordination between Cu and N atom in CHzyme.…”

Nanotechnology in reproduction, breeding and conservation of fish biodiversity: Current status and future potential

“…32 Recently, Wisdom et al 33 in their study successfully grafted chitosan on carbon nanotubes (20 nm) to reduce the toxicity of the latter in fish and may have an enormous potential to deliver various agents in the aquaculture species. Wisdom et al 34 developed chitosancarbon nanotube conjugates of 16 nm size to deliver nonapeptides, isotocin and vasotocin with the aim of oozing milt from the male C. magur by abdominal massaging. The results reveal that 80% of nonapeptides were conjugated with the chitosan-carbon nano grid which successfully released the high-quality milt from the fish.…”