Sustainable urbanisation in developing countries: cities as places to innovate, trade, and work

KEY MESSAGES: 1. Urbanisation and the creation of modern employment opportunities must be undertaken with greater climate considerations. 2. Cities can deliver on sustainable growth objectives by leveraging existing comparative advantages and building new ones. 3. Developing countries have natural endowments that can contribute to the net zero transition, opening up opportunities for urban industries and services. 4. Building the green cities of tomorrow can provide opportunities to absorb the large pool of low-skilled labour

Sustainable urbanisation in developing countries: cities as places to live

KEY MESSAGES: 1. Cities in developing countries are both the most vulnerable to climate change and the most viable solution to managing its impacts. 2. Urban density enables reduction in per capita emissions from infrastructure and services. 3. Access to local public goods and services aids resilience to environmental shocks and stressors. 4. Decisions about the city’s physical characteristics and infrastructure today will lock-in long-term consequences for the future

Origin and evolution of candidate mental retardation genes on the human X chromosome (MRX)

<p>Abstract</p> <p>Background</p> <p>The human X chromosome has a biased gene content. One group of genes that is over-represented on the human X are those expressed in the brain, explaining the large number of sex-linked mental retardation (MRX) syndromes.</p> <p>Results</p> <p>To determine if MRX genes were recruited to the X, or whether their brain-specific functions were acquired after relocation to the mammalian X chromosome, we examined the location and expression of their orthologues in marsupials, which diverged from human approximately 180 million years ago. We isolated and mapped nine tammar wallaby MRX homologues, finding that six were located on the tammar wallaby X (which represents the ancient conserved mammal X) and three on chromosome 5, representing the recently added region of the human X chromosome. The location of MRX genes within the same synteny groups in human and wallaby does not support the hypothesis that genes with an important function in the brain were recruited in multiple independent events from autosomes to the mammalian X chromosome. Most of the tammar wallaby MRX homologues were more widely expressed in tammar wallaby than in human. Only one, the tammar wallaby <it>ARX </it>homologue (located on tammar chromosome 5p), has a restricted expression pattern comparable to its pattern in human. The retention of the brain-specific expression of <it>ARX </it>over 180 million years suggests that this gene plays a fundamental role in mammalian brain development and function.</p> <p>Conclusion</p> <p>Our results suggest all the genes in this study may have originally had more general functions that became more specialised and important in brain function during evolution of humans and other placental mammals.</p