Posts Tagged ‘evolution’

The Monarch Butterfly Genome

February 21st, 2012

I know … this paper is not describing the genome of a plant or a fungus, but it is unraveling the 273 Mb genome of the superbe monarch butterfly — a migratory Lepideptora traveling long distance to reach its overwintering grounds in central America. Anyway, Danaus plexippus is interacting with plants and is thus welcome to fly over this blog.

The authors summarized their work as follows:

[We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16,866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny,and protein family sizes. The monarch genome reveals a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration.]

Read: Shuai Zhan, Christine Merlin, Jeffrey L. Boore and Steven M. Reppert (2011) The Monarch Butterfly Genome Yields Insights into Long-Distance Migration. Cell 147, 5, 1171-1185.

Figure. Life cycle of the monarch butterfly. Complete metamorphosis from egg to larva (five instars) to pupa (chrysalis) to adult. The male butterfly (upper right) has visible black spots on its hind wings that are missing in females (lower left, underwing view). The larvae feed on milkweed (plants of the genus Asclepias). Photograph of engraving from James Edward Smith, Natural History of the Rarer Lepidopterous Insects of Georgia; from the Observations of John Abbot, 1797.

See also: Monarch Butterfly Genome Begins to Open the Black Box

 

 

A Sneak Preview: ‘Effectors in Plant-Microbe Interactions’ book

September 17th, 2011

The book ‘Effectors in Plant-Microbe Interactions’

Edited by Sophien Kamoun and I, will be released by Wiley-Blackwell on January 2012:

A sneak preview …

Effectors are defined as molecules produced by bio-aggressors/pathogens/symbionts to manipulate their host plants, thereby facilitating infection (virulence or symbiotic factors, toxins, inhibitors) and/or triggering defense responses (avirulence factors, elicitors). This dual (and conflicting) activity of effectors has been broadly reported in many plant–microbial interactions. This research topic is actively investigated using a combination of approaches (genetics, molecular biology, biochemistry, physiology and developmental biology) and benefits from the recent advances in plant and microbial functional genomics and genome-wide evolutionary analyses. Tremendous progress has been made in recent years but many questions remain unanswered. The book aims to act as a catalyst for future research by bringing together a collection of contributions on plant–microbe interactions across a range of organisms (viruses, bacteria, fungi and nematodes) to identify and focus on these important questions. A book on this topic will be timely. It combines chapters by researchers involved in a diversity of plant-microbe systems that use biochemical, physiological, and developmental approaches as well as comparative genomics. Such a broad-ranging approach is providing a unique insight and a better understanding of the functions of this new class of proteins. Authors have been encouraged to discuss far reaching extensions of their current or past work and to propose cross-cutting research questions whenever possible.

Image: A great, arty photo from Sebastian Schornack (TSL) showing red fluorescent Phytophthora infestans colonizing its host. The central necrotrophic zone (in black) is surrounded by the biotrophic area (in fluo green).  The biotropic zone was caused by the action of effectors that suppressed the host responses.

 

The genome of a songbird

April 18th, 2010

Zebra_finchThe zebra finch (Taeniopygia guttata) is a songbird belonging to the large avian order Passeriformes. As the lovely bird lives in trees, it deserves a slot in this blog. This songbird genome has been sequenced and assembled, and the main results are presented in the 1st of April issue of Nature.

Of the 1.2 gigabase (Gb) draft assembly, 1.0 Gb has been assigned to 33 chromosomes and three linkage groups, by using zebra finch genetic linkage and bacterial artificial chromosome (BAC) fingerprint maps. A total of 17,475 protein-coding genes were predicted from the zebra finch genome assembly using the Ensembl pipeline supplemented by Gpipe gene models. A major result of this study the demonstration that song behaviour engages gene regulatory networks in the songbird brain, altering the expression of long non-coding RNAs, microRNAs, transcription factors and their targets. This study also suggests rapid molecular evolution in the songbird lineage of genes that are regulated during song experience. These results indicate an active involvement of the genome in neural processes underlying vocal communication.

Warren et al. (2010) The genome of a songbird. Nature 464, 757-762.

Photo: © mediawiki.org