Food selectivity of Bluegill and Green Sunfish Fry

Four genera of zooplankton and cladoceran egg cases, collected from a municipal sewage lagoon, were made available as food to green sunfish (Lepomis cyanellus) and bluegill (Lepomis macrochirus) fry, to examine their food selectivity. Green sunfish and bluegill fry ranged in size from 8.5-11.0 mm and 8.0-10.5 mm at stocking and were reared for 31 and 30 days, respectively. The gut contents of 1488 green sunfish and 1440 bluegill fry, representing day and night samples were examined. Diet composition was evaluated using the linear food selection index. Both green sunfish and bluegill fry selected for Cvclops vernalis and consistently selected against cladoceran egg cases and Potamocypris spp. Moina brachiata was consistently selected for by bluegills but was initially consumed by green sunfish in approximately the same proportion as they were available and later preferentially selected for by larger green sunfish fry. The mean length of prey species selected for, increased linearly with mean length of green sunfish fry; the food length relation for bluegill fry as the fish increased in size was curvilinear. There were no significant (P\u3e0.05) differences between day and night prey species and prey size selection. The number of prey organisms consumed by bluegill fry increased linearly with mean length of fish, and the differences between day and night quantities were significant (P≤0.05). The relationship between the number of prey organisms ingested and mean length of green sunfish fry was exponential. The differences in numbers of prey items ingested by green sunfish during lighted and dark hours were only significant (P≤0.05) for fry of mean total length 12.7 mm and greater

Prymnesins: Toxic Metabolites of the Golden Alga, Prymnesium parvum Carter (Haptophyta)

Increasingly over the past century, seasonal fish kills associated with toxic blooms of Prymnesium parvum have devastated aquaculture and native fish, shellfish, and mollusk populations worldwide. Protracted blooms of P. parvum can result in major disturbances to the local ecology and extensive monetary losses. Toxicity of this alga is attributed to a collection of compounds known as prymnesins, which exhibit potent cytotoxic, hemolytic, neurotoxic and ichthyotoxic effects. These secondary metabolites are especially damaging to gill-breathing organisms and they are believed to interact directly with plasma membranes, compromising integrity by permitting ion leakage. Several factors appear to function in the activation and potency of prymnesins including salinity, pH, ion availability, and growth phase. Prymnesins may function as defense compounds to prevent herbivory and some investigations suggest that they have allelopathic roles. Since the last extensive review was published, two prymnesins have been chemically characterized and ongoing investigations are aimed at the purification and analysis of numerous other toxic metabolites from this alga. More information is needed to unravel the mechanisms of prymnesin synthesis and the significance of these metabolites. Such work should greatly improve our limited understanding of the physiology and biochemistry of P. parvum and how to mitigate its blooms

Clinical molecular testing for ASXL1 c.1934dupG p.Gly646fs mutation in hematologic neoplasms in the NGS era.

ASXL1 (additional sex combs like 1) is a gene that is mutated in a number of hematological neoplasms. The most common genetic alteration is c.1934dupG p.Gly646fs. Previous publications have shown that ASXL1 mutations have a negative prognostic impact in patients with MDS and AML, however, controversy exists regarding the molecular testing of ASXL1 c.1934dupG as polymerase splippage over the adjacent homopolymer could lead to a false-positive result. Here, we report the first study to systematically test different targeted next generation sequencing (NGS) approaches for this mutation in patients with hematologic neoplasms. In addition, we investigated the impact of proofreading capabilities of different DNA polymerases on ASXL1 c.1934dupG somatic mutation using conventional Sanger sequencing, another common method for ASXL1 genotyping. Our results confirm that ASXL1 c.1934dupG can be detected as a technical artifact, which can be overcome by the use of appropriate enzymes and library preparation methods. A systematic study of serial samples from 30 patients show that ASXL1 c.1934dupG is a somatic mutation in haematological neoplasms including MDS, AML, MPN and MDS/MPN and often is associated with somatic mutations of TET2, EZH2, IDH2, RUNX1, NRAS and DNMT3A. The pattern of clonal evolution suggests that this ASXL1 mutation might be an early mutational event that occurs in the principal clonal population and can serve as a clonal marker for persistent/relapsing disease

Controlling Specimen Temperatures During Transport

This project provides an overview of the challenges, causes and interventions deployed associated with temperature monitoring compliance of laboratory specimens being transported by couriers from the Houston Area Locations to the Texas Medical Center.https://openworks.mdanderson.org/acif24/1012/thumbnail.jp