What sperm can teach us about energy production

Mammalian sperm have evolved under strict selection pressures that have resulted in a highly polarized and efficient design. A critical component of that design is the compartmentalization of specific metabolic pathways to specific regions of the cell. Although the restricted localization of mitochondria to the midpiece is the best known example of this design, the organization of the enzymes of glycolysis along the fibrous sheath is the primary focus of this review. Evolution of variants of these metabolic enzymes has allowed them to function when tethered, enabling localized energy production that is essential for sperm motility. We close by exploring how this design might be mimicked to provide an energy-producing platform technology for applications in nanobiotechnology.     

Demonstration of alternative feeds for the Pacific white shrimp, Litopenaeus vannamei, reared in low salinity waters of west Alabama

The replacement of marine proteins with vegetable proteins or terrestrial animal byproducts in aquaculture diets has been gaining momentum. This study examines the viability of replacing fish meal in shrimp production diets with alternative protein sources (combinations of vegetable proteins) in inland low salinity waters of west Alabama. The test diets were formulated to contain 36% protein and 8% lipid. The basal diet contained 10% fish meal. The fish meal was then replaced (on a weight to weight basis) with poultry meal (PM), pea meal or distiller's dried grain with solubles (DDGS). Two separate experiments (laboratory trial and farm trial) were devised to test the efficacy of the diets for Litopenaeus vannamei reared in low salinity waters. The laboratory trial was conducted at the E. W. Shell Fisheries Research Station in Auburn, Alabama, USA, whereas the farm trial examined the same diets in an outdoor flow-through system at a low salinity shrimp farm in west Alabama. Results indicate no significant differences in shrimp growth, weight gain, survival or feed conversion ratio among dietary treatments, suggesting that PM, pea meal and DDGS can serve as alternatives to fish meal as a protein source for shrimp reared in low salinity environments.     

Enhanced molecular identification of Botrytis spp. from New Zealand onions

Botrytis spp. associated with neck rot disease were isolated from New Zealand onions. The fungi were identified using molecular sequences of the ribosomal internal transcribed spacer (ITS) and intergenic spacer (IGS) regions, and the glyceraldehyde-3-phosphate dehydrogenase (G3PDH) gene. Analyses of the sequences showed that the majority of the isolates gathered in 2005–07 were B. aclada. A new high resolution melting analysis (HRMA) assay was developed that allowed fast and simple discrimination between B. aclada and other Botrytis spp. causing onion neck rot in New Zealand. To further verify these results, Botrytis isolates from New Zealand onions, stored in the International Collection of Microorganisms from Plants (ICMP), were also examined. Only a single isolate from the ICMP collection was B. aclada while two isolates were B. byssoidea, one B. squamosa and another closely related to Botryotinia porri. Identification of the remaining Botrytis isolates was more difficult; while IGS and ITS sequences indicated a close relationship to B. allii or B. byssoidea, a previously unreported intron insertion was observed at the 3′ end of the ribosomal small subunit gene in these isolates. No evidence of heterogeneity was observed in the G3PDH gene sequences, as might have been expected of the allodiploid B. allii, but the G3PDH sequence ruled out B. byssoidea as the identity of these isolates.     

Inspiring Change in Vermont and Beyond

In this speech, Travis Marcotte, Executive Director of the Intervale Center, shares the Center's innovation and leadership over the past 25+ years, from agricultural land reclamation, community-supported agriculture, riparian restoration, and large-scale composting to farm incubation, food hubs, community celebrations of local food, and more. Travis also shares how the Center is responding to climate change, healing the environment, and connecting people to good food and the profound benefits of a healthier food system.     

Intersex condition of shoal bass in the Flint River, Georgia

We examined male shoal bass Micropterus cataractae from the Flint River, Georgia, to determine the prevalence of intersex. During March and April 2010, we sampled 61 shoal bass from six sites along the Flint River. Testes were examined histologically and classified as intersex if the presence of oocytes was noted. Using a severity index, we compared samples collected on different dates and from different locations according to age and testis weight. No significant variations were noted among any of the groupings. Further investigation is needed to determine whether the intersex condition in shoal bass is severe enough to warrant concern and whether it is a natural phenomenon.     

Getting lost in the matrix? On how the characteristics and arrangement of linear landscape elements influence ecological connectivity

Landscape Ecology - Linear landscape elements (LLEs) such as ditches and hedgerows can increase the ecological connectivity of habitat embedded within agricultural areas by acting as corridors for...