Garner, B. | Search bioRxiv

bioRxiv2020

Reporting to the Convention on Biology Diversity: How are countries assessing and protecting their genetic diversity?

Genetic diversity is critically important for all species-domesticated and wild- to adapt to environmental change, and for ecosystem resilience to extreme events. International agreements such as the Convention on Biological Diversity (CBD) have committed to conserve and sustainably and equitably use all levels of biodiversity-genes, species and ecosystems-globally. However, assessment and monitoring of genetic diversity are often overlooked, and there are large knowledge and policy gaps regarding genetic diversity conservation. In this study, we present the first quantitative analysis of genetic diversity assessments conducted by Parties to the CBD. We conducted a detailed, systematic analysis of 114 CBD 5th (submitted 2014) and 6th (submitted 2018) National Reports to quantitatively assess actions, progress on targets, values and indicators related to genetic diversity. First, we found that the importance of genetic diversity is recognised by most Parties to the CBD, and that recognition increased over time. However, genetic targets mainly addressed genetic diversity within cultivated plants, farm animals, and crop wild relatives, with little focus on other wild species. Also, actions for conserving genetic diversity primarily concerned ex-situ facilities and policy, rather than monitoring and intervention for maintaining genetic diversity in situ. The most commonly used indicators of genetic diversity status were the number of genetic resources in conservation facilities, number of threatened breeds, and Red List Index, which are not well correlated to genetic erosion in most species -- highlighting that genetic change is poorly monitored by current indicators. Lastly, analyses of genetic data observations, indigenous use and knowledge of genetic diversity, and strategies being developed and implemented to conserve genetic diversity are highly under-reported. We make several recommendations for the post-2020 CBD Biodiversity Framework to improve awareness, assessment, and monitoring, and facilitate consistent and complete reporting of progress of genetic diversity in future National Reports. Article Impact StatementAn analysis of genetic diversity in CBD National Reports neglects non-domesticated species and demonstrates need for sufficient indicators.

scientific communication and education↗

bioRxiv2018

Identification of a novel tetrameric structure for human apolipoprotein-D

Apolipoprotein-D is a 25 kDa glycosylated member of the lipocalin family that folds into an eight-stranded {beta}-barrel with a single adjacent -helix. Apolipoprotein-D specifically binds a range of small hydrophobic ligands such as progesterone and arachidonic acid and has an antioxidant function that is in part due to the reduction of peroxidised lipids by methionine-93. Therefore, apolipoprotein-D plays multiple roles throughout the body and is protective in Alzheimers disease, where apolipoprotein-D overexpression reduces the amyloid-{beta} burden in Alzheimers disease mouse models.\n\nOligomerisation is a common feature of lipocalins that can influence ligand binding. The native structure of apolipoprotein-D, however, has not been conclusively defined. Apolipoprotein-D is generally described as a monomeric protein, although it dimerises when reducing peroxidised lipids.\n\nHere, we investigated the native structure of apolipoprotein-D derived from plasma, breast cyst fluid (BCF) and cerebrospinal fluid. In plasma and cerebrospinal fluid, apolipoprotein-D was present in high-molecular weight complexes, potentially in association with lipoproteins. In contrast, apolipoprotein-D in BCF formed distinct oligomeric species. We assessed apolipoprotein-D oligomerisation using native apolipoprotein-D purified from BCF and a suite of complementary methods, including multi-angle laser light scattering, analytical ultracentrifugation and small-angle X-ray scattering. Our analyses showed that apolipoprotein-D predominantly forms a {bsim}95 to {bsim}100 kDa tetramer. Small-angle X-ray scattering analysis confirmed these findings and provided a structural model for apolipoprotein-D tetramer. These data indicate apolipoprotein-D rarely exists as a free monomer under physiological conditions and provide insights into novel native structures of apolipoprotein-D and into oligomerisation behaviour in the lipocalin family.

biochemistry↗