ABSTRACT
Calanoid copepod populations are being severely affected due to the effects of ocean acidification (OA) and ocean warming (OW). These marine organisms are the most abundant primary consumers contributing significantly in the marine food web. Any effect on the abundance and diversity of copepods due to climate change is likely to have serious implications on the marine ecosystem functioning. Molecular studies that play a vital role in assessing the genetic changes under the influence of environmental imbalances are completely lacking for this species. Here we report the genetic variations in three generations of copepods through transcriptome sequencing. RNA sequencing was performed on an Illumina HiSeq platform employing the 2 × 100 bp paired-end chemistry. Approximately, 10GB of data was obtained for all the samples. The raw sequences were assembled through Trinity 2.6.6 and mined for single nucleotide polymorphisms (SNPs) and simple sequence repeats (SSRs). MIcroSAtellite Identification Tool (MISA) was used for SSR detection and Primer 3 (v 3.0) was utilized to design short oligonucleotide primers (18-20 mers). A total of 15,222 SSRs were identified and 28,944 primer pairs were designed against these motifs. The transcriptome possessed 413,890 SNPs at a frequency of 2.8 per kb. The newly discovered SSRs and SNPs could act as genetic markers for future studies on genetic diversity and conservation for Parvocalanus crassirostris.
ABSTRACT
Kuwait is a country with a very high dust loading; in fact it bears the world's highest particulate matter concentration in the outdoor air. The airborne dust often has associated biological materials, including pathogenic microbes that pose a serious risk to the urban ecosystem and public health. This study has established the baseline taxonomic characterization of microbes associated with dust transported into Kuwait from different trajectories. A high volume air sampler with six-stage cascade impactor was deployed for sample collection at a remote as well as an urban site. Samples from three different seasons (autumn, spring and summer) were subjected to targeted amplicon sequencing. A set of ~ 50 and 60 bacterial and fungal genera, respectively, established the core air microbiome. The predominant bacterial genera (relative abundance ≥ 1%) were Brevundimonas (12.5%), Sphingobium (3.3%), Sphingopyxis (2.7%), Pseudomonas (2.5%), Sphingomonas (2.4%), Massilia (2.3%), Acidovorax (2.0%), Allorhizobium (1.8%), Halomonas (1.3%), and Mesorhizobium (1.1%), and the fungal taxa were Cryptococcus (12%) followed by Alternaria (9%), Aspergillus (7%), Candida (3%), Cladosporium (2.9%), Schizophyllum (1.6%), Fusarium (1.4%), Gleotinia (1.3%) and Penicillium (1.15%). Significant spatio-temporal variations were recorded in terms of relative abundances, α-diversities, and ß-diversities of bacterial communities. The dissimilarities were less pronounced and instead the communities were fairly homogenous. Linear discrimant analysis revealed three fungal genera known to be significantly differentially abundant with respect to different size fractions of dust. Our results shed light on the spatio-temporal distribution of airborne microbes and their implications in general health.
