From Mendel’s discovery on pea to today’s plant genetics and breeding

In 2015, we celebrated the 150th anniversary of the presentation of the seminal work of Gregor Johann Mendel. While Darwin’s theory of evolution was based on differential survival and differential reproductive success, Mendel’s theory of heredity relies on equality and stability throughout all stages of the life cycle. Darwin’s concepts were continuous variation and “soft” heredity; Mendel espoused discontinuous variation and “hard” heredity. Thus, the combination of Mendelian genetics with Darwin’s theory of natural selection was the process that resulted in the modern synthesis of evolutionary biology. Although biology, genetics, and genomics have been revolutionized in recent years, modern genetics will forever rely on simple principles founded on pea breeding using seven single gene characters. Purposeful use of mutants to study gene function is one of the essential tools of modern genetics. Today, over 100 plant species genomes have been sequenced. Mapping populations and their use in segregation of molecular markers and marker–trait association to map and isolate genes, were developed on the basis of Mendel's work. Genome-wide or genomic selection is a recent approach for the development of improved breeding lines. The analysis of complex traits has been enhanced by high-throughput phenotyping and developments in statistical and modeling methods for the analysis of phenotypic data. Introgression of novel alleles from landraces and wild relatives widens genetic diversity and improves traits; transgenic methodologies allow for the introduction of novel genes from diverse sources, and gene editing approaches offer possibilities to manipulate gene in a precise manner

In what sense does 'nothing make sense except in the light of evolution'?

Dobzhansky argued that biology only makes sense if life on earth has a shared history. But his dictum is often reinterpreted to mean that biology only makes sense in the light of adaptation. Some philosophers of science have argued in this spirit that all work in ‘proximal’ biosciences such as anatomy, physiology and molecular biology must be framed, at least implicitly, by the selection histories of the organisms under study. Others have denied this and have proposed non-evolutionary ways in which biologists can frame these investigations. This paper argues that an evolutionary perspective is indeed necessary, but that it must be a forward-looking perspective informed by a general understanding of the evolutionary process, not a backward-looking perspective informed by the specific evolutionary history of the species being studied. Interestingly, it turns out that there are aspects of proximal biology that even a creationist cannot study except in the light of a theory of their effect on future evolutio

Five misunderstandings about case-study research

When I first became interested in in-depth case-study research, I was trying to understand how power and rationality shape each other and form the urban environments in which we live (Flyvbjerg, 1998). It was clear to me that in order to understand a complex issue like this, in-depth case-study research was necessary. It was equally clear, however, that my teachers and colleagues kept dissuading me from employing this particular research methodology. ‘You cannot generalize from a single case’, some would say, ‘and social science is about generalizing. ’ Others would argue that the case study may be well suited for pilot studies but not for full-fledged research schemes. Others again would comment that the case study is subjective, giving too much scope for the researcher’s own interpretations. Thus the validity of case studies would be wanting, they argued. At first, I did not know how to respond to such claims, which clearly formed the conventional wisdom about case-study research. I decided therefore to find out where the claims come from and whether they are correct. This chapter contains what I discovered

Cloning and characterization of a novel 2-ketoisovalerate reductase from the beauvericin producer Fusarium proliferatum LF061

<p>Abstract</p> <p>Background</p> <p>The ketoisovalerate reductase (EC 1.2.7.7 ) is required for the formation of beauvericin via the nonribosomal peptide synthetase biosynthetic pathway. It catalyzes the NADPH-specific reduction of ketoisovaleric acid to hydroxyisovalerate. However, little is known about the bioinformatics’ data about the 2-Kiv reductase in <it>Fusarium</it>. To date, heterologous production of the gene <it>KivRFp</it> from <it>Fusarium</it> has not been achieved.</p> <p>Results</p> <p>The <it>KivRFp</it> gene was subcloned and expressed in <it>Escherichia coli</it> BL21 using the pET expression system. The gene <it>KivRFp</it> contained a 1,359 bp open reading frame (ORF) encoding a polypeptide of 452 amino acids with a molecular mass of 52 kDa. Sequence analysis indicated that it showed 61% and 52% amino acid identities to ketoisovalerate reductase from <it>Beauveria bassiana</it> ATCC 7159 (ACI30654) and <it>Metarhizium acridum</it> CQMa 102 (EFY89891), respectively; and several conserved regions were identified, including the putative nucleotide-binding signature site, GXGXXG, a catalytic triad (Glu405, Asn184, and Lys285). The KivRFp exhibited the highest activity at 35°C and pH 7.5 respectively, by reduction of ketoisovalerate. It also exhibited the high level of stability over wide temperature and pH spectra and in the presence of metal ions or detergents.</p> <p>Conclusions</p> <p>A new ketoisovalerate reductase KivRFp was identified and characterized from the depsipeptide-producing fungus <it>F</it>. <it>proliferatum</it>. KivRFp has been shown to have useful properties, such as moderate thermal stability and broad pH optima, and may serve as the starting points for future protein engineering and directed evolution, towards the goal of developing efficient enzyme for downstream biotechnological applications.</p