Bryophytes new to Crete

Abstract

The prinicpal soluble carbohydrate of 10 axenically cultured species of liverwort are qualitatively identical with those from the field. It can therefore be concluded that they are synthesised primarily by the liverwort tissue and cannot be attributed to any fungal hyphae present in field material. The possibility remains that trace amounts of hexitol are synthesized by fungal endophytes. In chemotaxonomic studies based on field material therefore, the principal soluble carbohydrates present, particularly alditols, may be ascribed to an hepatic rather than a fungal origin.     

A new strategy to infer circularity applied to four new complete frog mitogenomes

We applied a novel strategy to infer sequence circularity and complete assembly of four mitochondrial genomes (mitogenomes) of the frog families Bufonidae (Melanophryniscus moreirae), Dendrobatidae (Hyloxalus subpunctatus and Phyllobates terribilis), and Scaphiopodidae (Scaphiopus holbrookii). These are the first complete mitogenomes of these four genera and Scaphiopodidae. We assembled mitogenomes from short genomic sequence reads using a baiting and iterative mapping strategy followed by a new ad hoc mapping strategy developed to test for assembly circularization. To assess the quality of the inferred circularization, we used Bowtie2 alignment scores and a new per‐position sequence coverage value (which we named “connectivity”). Permutation tests with 400 iterations per specimen and 1% or 5% chance of mutation at the ends of the putative circular sequences showed that the proposed method is highly sensitive, with a single nucleotide insertion or deletion being sufficient for circularity to be rejected. False positives comprised only 2% of all observations and possessed significantly lower alignment scores. The size, gene content, and gene arrangement of each mitogenome differed among the species but matched the expectations for their clades. We argue that basic studies on circular sequences can benefit from the results and bioinformatics procedures introduced here, especially when closely related references are lacking.     

Evo-devo graduates to new levels

The second symposium on 'The Developmental Basis of Evolutionary Change' was held at the University of Chicago, IL, USA, from 25 to 28 October 2001.     

A new licence to clone

Many countries are still grappling with the issue of therapeutic cloning of human cells as the UN tackles this issue alongside reproductive cloning, but in the UK a new programme looking at the causes of motor neuron disease has recently been sanctioned. Michael Gross reports.     

Adjusting to your new job

Having done the hard work in winning your new job, you might find fitting into a new environment to be just as demanding. Don't make the common mistake of focusing solely on work and getting results. You need to pay equal attention to nurturing good relationships with your new colleagues. Here are a few more hints to help ensure that you get off to the best possible start.