The massive arrival of Sargassum biomass on the Caribbean coast is a potential raw material source that needs an assessment of its quality and preservation state. Thus, the present study aimed to investigate how pelagic Sargassum changes its chemical composition due to sample transportation, morphotype (S. natans I, S. natans VIII, and S. fluitans III), and exposure to open-air conditions during two months of outdoor conditions using Fourier Transform Infra-Red (IR) spectroscopy and chemometric analysis. The results demonstrate that cold transportation to the lab before flash-freezing caused sample degradation, characterized by mannitol consumption and the formation of anaerobic metabolism products. Multivariate analyses showed that the IR spectral zone with differences between S. natans and S. fluitans were in the same IR spectral regions related to sample degradation. In the two flash-freezing treatments, S. fluitans had the highest IR peak absorbance of mannitol and a lower absorbance for the carboxylic acids IR peak. Between S. natans morphotypes, S. natans I had the highest modification caused by the cold transportation to the lab. The decomposition under prolonged time (up to eight weeks) in open-air conditions demonstrated an increased absorbance on the IR bands of carboxylic acids in the first four weeks. In the sixth and eighth weeks, the IR signals of calcium carbonate increased more than those from organic matter. This study provides a better understanding of the importance of preserving the collected samples and how the decomposition dynamics of Sargassum species may impact the extraction of key compounds, e.g., alginate and mannitol.

The Pelibuey sheep (Ovis aries) is an indigenous breed distributed in the tropical regions of Mexico. The prolificacy of this sheep is on average from 1 to 1.5 lambs, being an important breeding characteristic that owners seek to increase with the purpose of economic improvements. New-generation RNA sequencing technology has been used to identify the genes that are expressed in the ovarian tissue of sheep that have two or more lambs per parturition, as well as to elucidate the metabolic pathways that are affected by the expression of these genes, with the purpose of better understanding the prolificacy in the sheep. In the present study, the transcriptional expression of multiparous and uniparous sheep was compared using RNA sequencing. Multiparous (M group) and uniparous (U group) sheep that had a genealogical record for three generations (M, n = 5 and U, n = 5) were selected. RNA was extracted from ovarian tissue and subsequently used to prepare the libraries that were sequenced using the Illumina NextSeq500 platform. A total of 31,575 genes were detected from the transcriptomic analysis of which 4908 were significantly expressed (p-value ≤ 0.001) in the ovary of sheep. Subsequently, a second filter was carried out to evaluate the false discovery rate (FDR) and select those genes with p-values ≤ 0.05 and values of expression ≥ 1 (log2), obtaining 354 differential expressed genes (DEG): 120 genes up-regulated and 234 genes down-regulated in the group M with respect to the group U. Through Gene Ontology (GO) and metabolic analysis, we obtained information on the function of differentially expressed genes, and its importance in the reproduction of multiparous sheep. This result suggest that genes identified in the present study participate in the development of the final stages of follicles.

Marine gastropods of the genus Conus, comprising more than 800 species, have the characteristic of injecting worms and other prey with venom. These conopeptide toxins, highly diverse in structure and action, are highly potent and specific for their molecular targets (ion channels, receptors, and transporters of the prey’s nervous system), and thus are important research tools and source for drug discovery. Next-generation sequencing technologies are speeding up the discovery of novel conopeptides in many of these species, but only limited information is available for Conus spurius, which inhabits sandy mud. To search for new precursor conopeptides, we analyzed the transcriptome of the venous ducts of C. spurius and identified 55 putative conotoxins. Seven were selected for further study and confirmed by Sanger sequencing to belong to the M-superfamily (Sr3.M01 and Sr3.M02), A-superfamily (Sr1.A01 and Sr1.A02), O-superfamily (Sr15.O01), and Con-ikot-ikot (Sr21.CII01 and Sr22.CII02). Six of these have never been reported. To our knowledge, this report is the first to use high-throughput RNA sequencing for the study of the diversity of C. spurius conotoxins.