People with autism have a wide range of symptoms, with no two people sharing the exact type and severity of behaviors. Now a large-scale analysis of hundreds of patients and nearly 1000 genes has started to uncover how diversity among traits can be traced to differences in patients’ genetic mutations. The study, conducted by researchers at Columbia University Medical Center, was published Dec. 22 in the journal Nature Neuroscience.
Autism researchers have identified hundreds of genes that, when mutated, likely increase the risk of developing autism spectrum disorder (ASD). Much of the variability among people with ASD is thought to stem from the diversity of underlying genetic changes, including the specific genes mutated and the severity of the mutation.
“If we can understand how different mutations lead to different features of ASD, we may be able to use patients’ genetic profiles to develop accurate diagnostic and prognostic tools and perhaps personalize treatment,” said senior author Dennis Vitkup, PhD, associate professor of systems biology and biomedical informatics at Columbia University’s College of Physicians & Surgeons.
Jonathan Chang, Sarah R Gilman, Andrew H Chiang, Stephan J Sanders, Dennis Vitkup. Genotype to phenotype relationships in autism spectrum disorders.Nature Neuroscience, 2014; DOI: 10.1038/nn.3907
Sex Questioning is a process of exploration by people who may be unsure, still exploring, and concerned about applying a sex label to themselves for various reasons.
Colors from this flag by@protego-et-servio using -genital flags format, however sex questioning could be more than just genital, could apply to question your genotype, karyotype/chromosomes, gonads and so on. Not always questioning if they are intersex but could also altersex, perisex, parsex or protosex.
Single plant cells have amazing capacities for regenerating into entire plants. This property is known as ‘totipotency’ discovered in the 1920s. Linking this with increasing understanding of growth control by plant hormones resulted in the development of the sterile, in vitro, culture. Tiny groups of cells, explants, are cut from the rapidly growing tips of shoots in controlled environments and washed in sterilising agents. These are cultured sterile jars containing a layer of agar supplemented with nutrients and hormones.
Green plantlets growing on sterile agar
The process is known as ‘tissue culture’ or micropropagation. As the cells divide and multiply, they are transferred through a series of sterile conditions which encourage root formation.
Roots growing from newly developing plantlets
Ultimately numerous new whole plants are generated. At that point they are removed from sterile conditions and weaned by planting into clean compost in high humidity environments. High humidity is essential as these transplants lack the protective coating of leaf and stem waxes which prevent desiccation. Ultimately when fully weaned the plants are grown under normal nursery conditions into saleable products.
Why bother with this processes which requires expensive facilities and highly skilled staff? A prime advantage is that micropropagated plants have genotypes very closely similar to those of the original parent, essentially they are clones. As a result vast numbers of progeny can be generated from a few parents preserving their characteristics. That is particularly important as a means of bulking-up newly bred varieties of many ornamental and fruit producing plants which otherwise would be reproduced vegetatively from cuttings or by grafting and budding onto rootstocks. Micropropagation is therefore a means for safeguarding the intellectual property of plant breeding companies.
Explants cut from parent plants before culturing can be heat-treated as a means of removing virus infections. The resultant end-products of rooted plants are therefore disease-free or more accurately disease-tested. These plants are usually more vigorous and produce bigger yields of flowers and fruit. Orchids are one of the crops where the impact of micropropagation is most obvious in florists’ shops and supermarkets.
Orchids have benefitted greatly from micropropagation
Large numbers of highly attractive orchids are now readily available. Previously orchids were very expensive and available in sparse numbers.
The world is not perfect and there are disadvantages with micropropagation. Because the progeny are genetically similar they are uniformly susceptible to pests and pathogens. Crops of clonal plants can be and have been rapidly devasted by existing and new strains of insects and diseases to which they have no resistance.
Written by: Professor Geoff Dixon, author of Garden practices and their science (ISBN 978-1-138-20906-0) published by Routledge 2019.
