College of Agriculture & Natural Resources
Permanent URI for this communityhttp://hdl.handle.net/1903/1598
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
Browse
4 results
Search Results
Item DNA methylation profiles correlated to striped bass sperm fertility(Springer Nature, 2018-04-10) Woods, L. Curry III; Li, Yaokun; Ding, Yi; Liu, Jianan; Reading, Benjamin J.; Fuller, S. Adam; Song, JiuzhouStriped bass (Morone saxatilis) spermatozoa are used to fertilize in vitro the eggs of white bass (M. chrysops) to produce the preferred hybrid for the striped bass aquaculture industry. Currently, only one source of domestic striped bass juveniles is available to growers that is not obtained from wild-caught parents and is thus devoid of any genetic improvement in phenotypic traits of importance to aquaculture. Sperm epigenetic modification has been predicted to be associated with fertility, which could switch genes on and off without changing the DNA sequence itself. DNA methylation is one of the most common epigenetic modification types and changes in sperm epigenetics can be correlated to sub-fertility or infertility in male striped bass. The objective of this study was to find the differentially methylated regions (DMRs) between high-fertility and sub-fertility male striped bass, which could potentially regulate the fertility performance. In our present study, we performed DNA methylation analysis of high-fertility and sub-fertility striped bass spermatozoa through MBD-Seq methods. A total of 171 DMRs were discovered in striped bass sperm correlated to fertility. Based on the annotation of these DMRs, we conducted a functional classification analysis and two important groups of genes including the WDR3/UTP12 and GPCR families, were discovered to be related to fertility performance of striped bass. Proteins from the WDR3/UTP12 family are involved in forming the sperm flagella apparatus in vertebrates and GPCRs are involved in hormonal signaling and regulation of tissue development, proliferation and differentiation. Our results contribute insights into understanding the mechanism of fertility in striped bass, which will provide powerful tools to maximize reproductive efficiencies and to identify those males with superior gametes for this important aquaculture species.Item Analysis of the fecal microbiota of fast- and slow-growing rainbow trout (Oncorhynchus mykiss)(Springer Nature, 2019-10-29) Chapagain, Pratima; Arivett, Brock; Cleveland, Beth M.; Walker, Donald M.; Salem, MohamedDiverse microbial communities colonizing the intestine of fish contribute to their growth, digestion, nutrition, and immune function. We hypothesized that fecal samples representing the gut microbiota of rainbow trout could be associated with differential growth rates observed in fish breeding programs. If true, harnessing the functionality of this microbiota can improve the profitability of aquaculture. The first objective of this study was to test this hypothesis if gut microbiota is associated with fish growth rate (body weight). Four full-sibling families were stocked in the same tank and fed an identical diet. Two fast-growing and two slow-growing fish were selected from each family for 16S rRNA microbiota profiling.Item Distinct microbial assemblages associated with genetic selection for high- and low- muscle yield in rainbow trout(Springer Nature, 2020-11-23) Chapagain, Pratima; Walker, Donald; Leeds, Tim; Cleveland, Beth M.; Salem, MohamedFish gut microbial assemblages play a crucial role in the growth rate, metabolism, and immunity of the host. We hypothesized that the gut microbiota of rainbow trout was correlated with breeding program based genetic selection for muscle yield. To test this hypothesis, fecal samples from 19 fish representing an F2 high-muscle genetic line (ARS-FY-H) and 20 fish representing an F1 low-muscle yield genetic line (ARS-FY-L) were chosen for microbiota profiling using the 16S rRNA gene. Significant differences in microbial assemblages between these two genetic lines might represent the effect of host genetic selection in structuring the gut microbiota of the host. Tukey’s transformed inverse Simpson indices indicated that high muscle yield genetic line (ARS-FY-H) samples have higher microbial diversity compared to those of the low muscle yield genetic line (ARS-FY-L) (LMM, χ2(1) =14.11, p < 0.05). The fecal samples showed statistically distinct structure in microbial assemblages between the genetic lines (F1,36 = 4.7, p < 0.05, R2 = 11.9%). Functional profiling of bacterial operational taxonomic units predicted characteristic functional capabilities of the microbial communities in the high (ARS-FY-H) and low (ARS-FY-L) muscle yield genetic line samples. The significant differences of the microbial assemblages between high (ARS-FY-H) and low (ARS-FY-L) muscle yield genetic lines indicate a possible effect of genetic selection on the microbial diversity of the host. The functional composition of taxa demonstrates a correlation between bacteria and improving the muscle accretion in the host, probably, by producing various metabolites and enzymes that might aid in digestion. Further research is required to elucidate the mechanisms involved in shaping the microbial community through host genetic selection.Item Toward the Development of Integrated Oyster-Algae Aquaculture in the Chesapeake Bay(2014) Ray, Nicholas; Kangas, Patrick C; Environmental Science and Technology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Oyster aquaculture is a rapidly expanding industry in the Chesapeake Bay. Experiments were conducted to investigate the biogeochemical impact of a commercial oyster aquaculture facility on downstream waters at a facility on Maryland's Eastern Shore. An algal production system (ATS) was installed at the facility to assess the potential for bioremediation and algal production in an integrated multi-trophic aquaculture system (IMTA). Results of the experiments showed an increase in available ammonia downstream of the aquaculture facility, coupled with decreases in dissolved oxygen and total phytoplankton. The algal production system demonstrated an average productivity rate of 82.8 g/m2*day-1, a nitrogen (N) removal rate of 9.6 gN/m2*day-1, a phosphorus (P) removal rate of 0.20 gP/m2*day-1, and harvests consisted of an average of 7.8% organic content. Productivity and N and P removal rates from this study are higher than other systems tested in the Chesapeake Bay region at sites without an aquaculture facility.