Genetics of Growth Reaction Norms in Farmed Rainbow Trout

Rainbow trout is farmed globally under diverse uncontrollable environments. Fish with low macroenvironmental sensitivity (ES) of growth is important to thrive and grow under these uncontrollable environments. The ES may evolve as a correlated response to selection for growth in one environment when the genetic correlation between ES and growth is nonzero. The aims of this study were to quantify additive genetic variance for ES of body weight (BW), defined as the slope of reaction norm across breeding environment (BE) and production environment (PE), and to estimate the genetic correlation (r _{g(int, sl)}) between BW and ES. To estimate heritable variance of ES, the coheritability of ES was derived using selection index theory. The BW records from 43,040 rainbow trout performing either in freshwater or seawater were analysed using a reaction norm model. High additive genetic variance for ES (9584) was observed, inferring that genetic changes in ES can be expected. The coheritability for ES was either -0.06 (intercept at PE) or -0.08 (intercept at BE), suggesting that BW observation in either PE or BE results in low accuracy of selection for ES. Yet, the r _{g(int, sl)} was negative (-0.41 to -0.33) indicating that selection for BW in one environment is expected to result in more sensitive fish. To avoid an increase of ES while selecting for BW, it is possible to have equal genetic gain in BW in both environments so that ES is maintained stable.     

Aortic aneurysm formation following coarctation repair by Dacron patch aortoplasty

We describe the finding of an aortic aneurysm in an asymptomatic 43-year-old male, who was managed by Dacron patch aortoplasty for native coarctation of the aorta 25 years before. The role of magnetic resonance angiography as standard imaging technique in lifelong postoperative surveillance is discussed subsequently. (Neth Heart J 2010;18:376-7.)     

Gene expression patterns in anterior pituitary associated with quantitative measure of oestrous behaviour in dairy cows

Intensive selection for high milk yield in dairy cows has raised production levels substantially but at the cost of reduced fertility, which manifests in different ways including reduced expression of oestrous behaviour. The genomic regulation of oestrous behaviour in bovines remains largely unknown. Here, we aimed to identify and study those genes that were associated with oestrous behaviour among genes expressed in the bovine anterior pituitary either at the start of oestrous cycle or at the mid-cycle (around day 12 of cycle), or regardless of the phase of cycle. Oestrous behaviour was recorded in each of 28 primiparous cows from 30 days in milk onwards till the day of their sacrifice (between 77 and 139 days in milk) and quantified as heat scores. An average heat score value was calculated for each cow from heat scores observed during consecutive oestrous cycles excluding the cycle on the day of sacrifice. A microarray experiment was designed to measure gene expression in the anterior pituitary of these cows, 14 of which were sacrificed at the start of oestrous cycle (day 0) and 14 around day 12 of cycle (day 12). Gene expression was modelled as a function of the orthogonally transformed average heat score values using a Bayesian hierarchical mixed model on data from day 0 cows alone (analysis 1), day 12 cows alone (analysis 2) and the combined data from day 0 and day 12 cows (analysis 3). Genes whose expression patterns showed significant linear or non-linear relationships with average heat scores were identified in all three analyses (177, 142 and 118 genes, respectively). Gene ontology terms enriched among genes identified in analysis 1 revealed processes associated with expression of oestrous behaviour whereas the terms enriched among genes identified in analysis 2 and 3 were general processes which may facilitate proper expression of oestrous behaviour at the subsequent oestrus. Studying these genes will help to improve our understanding of the genomic regulation of oestrous behaviour, ultimately leading to better management strategies and tools to improve or monitor reproductive performance in bovines.     

Ontogeny of male plumage dichromatism in Madagascar paradise flycatchers Terpsiphone mutata

Two male plumage morphs, 'white' and 'rufous', coexist in the Madagascar paradise flycatcher Terpsiphone mutata . There has been enduring debate about whether this dimorphism in male plumage represents seasonal dichromatism, delayed plumage maturation, or genetic differences. We present data from a nine-year study monitoring plumage changes in 119 individually colour-banded males (430 male-years). Our data show that paradise flycatchers are not seasonally dichromatic, and that although males show delayed plumage maturation, the rufous morph is not simply a precursor to white plumage, as previously thought. Individual males followed irreversible developmental pathways to 'rufous' or 'white', and could be reliably assigned to these distinct phenotypes by their second year. 'White' males adopted definitive plumage by the age of three years, whereas 'rufous' males did so between the ages of three and six years. The fixed nature of these morphs suggests that a genetic basis for the dichromatism is likely. However, variation in the timing of definitive plumage acquisition in rufous males could involve condition dependence and be environmentally influenced.     

<Emphasis Type="Italic">Dracunculus mulbus</Emphasis> n. sp. (Nematoda: Spirurida) from the water python <Emphasis Type="Italic">Liasis fuscus</Emphasis> (Serpentes: Boidae) in northern Australia

A new species of Dracunculus Reichard, 1759 (Nematoda: Spirurida) is described from the tissues surrounding organs in the body-cavity of the water python Liasis fuscus Peters in northern Australia. One to 14 worms were recovered from 22% (27/120) of pythons examined. Males were located principally around the lungs, liver and heart of the hosts, and females were recovered from peritoneal tissue surrounding the intestines and lining the body-cavity. This species differs from previously described species of Dracunculus in the position of the papillae at the posterior end in males, and in the possession of thick, narrow caudal alae. Submedian cephalic papillae are single in both sexes. Dorsal and ventral anterior cephalic papillae are absent in males. This is the first report of a species of Dracunculus from the Australian region.     

The minimum information required for reporting a molecular interaction experiment (MIMIx)

A wealth of molecular interaction data is available in the literature, ranging from large-scale datasets to a single interaction confirmed by several different techniques. These data are all too often reported either as free text or in tables of variable format, and are often missing key pieces of information essential for a full understanding of the experiment. Here we propose MIMIx, the minimum information required for reporting a molecular interaction experiment. Adherence to these reporting guidelines will result in publications of increased clarity and usefulness to the scientific community and will support the rapid, systematic capture of molecular interaction data in public databases, thereby improving access to valuable interaction data.     

Protein-liposome conjugates using cysteine-lipids and native chemical ligation

Liposomes have become popular drug delivery vehicles and have more recently also been applied as contrast agents for molecular imaging. Most current methods for functionalization of liposomes with targeting proteins rely on reactions of amine or thiol groups at the protein exterior, which generally result in nonspecific conjugation at multiple sites on the protein. In this study, we present native chemical ligation (NCL) as a general method to covalently couple recombinant proteins in a highly specific and chemoselective way to liposomes containing cysteine-functionalized phospholipids. A cysteine-functionalized phospholipid (Cys-PEG-DSPE) was prepared and shown to readily react with the MESNA thioester of EYFP, which was used as a model protein. Characterization of the EYFP-liposomes using fluorescence spectroscopy showed full retention of the fluorescent properties of conjugated EYFP and provides a lower limit of 120 proteins per liposome. The general applicability of NCL was further tested using CNA35, a collagen-binding protein recently applied in fluorescent imaging of collagen. NCL of CNA35 thioester yielded liposomes containing approximately 100 copies of CNA35 per liposome. The CNA35-liposomes were shown to be fully functional and bind collagen with a 150-fold higher affinity compared to CNA35. Our results show that NCL is an attractive addition to existing conjugation methods that allows direct, covalent, and highly specific coupling of recombinant proteins to liposomes and other lipid-based assemblies.     

Function of pair duets in the eastern whipbird: cooperative defense or sexual conflict?

Paired male and female eastern whipbirds, Psophodes olivaceus,sing precisely coordinated, male-led duets. Four broad explanationshave been proposed for the function of duets: 1) cooperativeresource defense, 2) prevention of partner usurpation, 3) defenseof an individual's own position within the partnership, or 4)mate identification and localization. These 4 hypotheses makedifferent predictions about how male and female residents shouldrespond to simulated intrusion by other pairs or individuals.We compared the behavioral and vocal responses of 20 pairs ofeastern whipbirds to simulated territorial intrusions by: 1)a solitary singing male, 2) a solitary singing female, and 3)a duetting pair. Males and females did not coordinate theirapproach to the playback speaker and showed sex-specific responsesto playback. Males did not respond differently to duetting versussolo singing intruders. By contrast, females approached moreclosely during solo female song than during solo male song orduet playback. Females also produced specific vocalizationsonly in response to duet and solo female playback. Both sexesapproached the speaker more closely and quickly during playbackof same-sex solo songs than opposite-sex solo songs. Finally,females answered more of their mate's songs during simulatedintrusion by a lone female than during simulated intrusion bya lone male. Our results suggest that duets in this speciesprimarily function to allow females to defend their exclusiveposition in a partnership. Mate defense by females is unusualin birds but may be promoted in eastern whipbirds by a female-biasedsex ratio and the need for exclusive access to male care. Thus,duets result from independent and conflicting strategies ofmate and territory defense in males and females.