Tumorigenesis is a complex process that is regulated by a variety of network signals. With the continuous development of the process, tumor cells gradually exhibit lots of hallmarks.Tumor cells have the characteristics of unlimited proliferation, resistance to apoptosis, evading immune surveillance, among others. As a unique organelles, mitochondria play an important role in cellular energy metabolism, reactive oxygen species producing and apoptosis process. Particularly, mitochondria have a close relationship with tumor development. In this review, we focus on the essential role of mitochondria in tumor cells development.
Animals ; Energy Metabolism ; Humans ; Mitochondria ; metabolism ; physiology ; Neoplasms ; etiology ; genetics ; physiopathology ; Tumor Microenvironment ; physiology

Fhx/P25 in silkworm, Bombyx mori, one of the main components of silk fibroin, is presumed in previous reports to be expressed exclusively in the posterior silk gland (PSG) of the animal with strict territorial and developmental specificities. On the basis of a large-scale analysis ofthe silkworm EST data, it was found that Fhx/P25 gene is transcribed not only in the posterior silk gland, but in the ovary and in other tissues of the larvae at day 3 of the fifth-instar as well and that this gene has distinct transcription start sites (TSSs) in the posterior silk gland and the ovary. The TSS in the ovary is located about 115 bp upstream sequence of that in the posterior silk gland. Subsequent RT-PCR, FQ-PCR and sequencing have verified the validity of this presumption. In addition, alternative splicing is predicted in pre-mRNA of Fhx/P25 gene and confirmed by RT-PCR. In conclusion, Fhx/P25 gene is not a gene with strictly tissue-specific transcription.Complicated regulation mechanisms may exist for its transcription and expression and it may have other functions to perform.

Microsatellites or simple sequence repeats (SSRs) have been found in most organisms during the last decade. Since large-scale sequences are being generated, especially those that can be used to search for microsatellites, the development of these markers is getting more convenient. Keeping SSRs in viewing the importance of the application, available CDS (coding sequences) or ESTs (expressed sequence tags) of some eukaryotic species were used to study the frequency and density of various types of microsatellites. On the basis of surveying CDS or EST sequences amounting to 66.6 Mb in silkworm, 37.2 Mb in fly, 20.8 Mb in mosquito, 60.0 Mb in mouse, 34.9 Mb in zebrafish and 33.5 Mb in Caenorhabditis elegans, the frequency of SSRs was 1/1.00 Kb in silkworm, 1/0.77 Kb in fly, 1/1.03 Kb in mosquito, 1/1.21 Kb in mouse, 1/1.25 Kb in zebrafish and 1/1.38 Kb in C. elegans. The overall average SSR frequency of these species is 1/1.07 Kb. Hexanucleotide repeats (64.5%-76.6%) are the most abundant class of SSR in the investigated species, followed by trimeric, dimeric, tetrameric, monomeric and pentameric repeats. Furthermore, the A-rich repeats are predominant in each type of SSRs, whereas G-rich repeats are rare in the coding regions.
Animals ; Anopheles ; genetics ; Bombyx ; genetics ; Caenorhabditis elegans ; genetics ; Drosophila melanogaster ; genetics ; Expressed Sequence Tags ; Genome ; Invertebrates ; genetics ; Mice ; genetics ; Microsatellite Repeats ; genetics ; Zebrafish ; genetics

Silk-based biomaterials are featured with excellent mechanical properties, good biocompatibility and biodegradability, which contribute to their potential applications in biomedical field. The current recognition of silk protein materials in structure and function provides a basic theory for the transformation of silk protein into new types of biomaterials. In addition, exogenous sequences encoding new peptide or structural domain can be inserted into the maternal gene sequences encoding silk proteins through genetic engineering technology to synthesize novel silk-based biomaterials with unique functions. This review summarizes the current trend and development perspective of genetically engineered functional silk-based materials for biomedical applications.
Biocompatible Materials ; Genetic Engineering ; Hydrogels ; Silk

Multiple plant lineages have independently evolved sex chromosomes and variable kary-otypes to maintain their sessile lifestyles through constant biological innovation.Morus notabilis,a dioecious mulberry species,has the fewest chromosomes among Morus spp.,but the genetic basis of sex determination and karyotype evolution in this species has not been identified.In this study,three high-quality genome assemblies were generated for Morus spp.[including dioecious M.notabilis(male and female)and Morus yunnanensis(female)]with genome sizes of 301-329 Mb and were grouped into six pseudochromosomes.Using a combination of genomic approaches,we found that the putative ancestral karyotype of Morus species was close to 14 protochromosomes,and that sev-eral chromosome fusion events resulted in descending dysploidy(2n=2x=12).We also charac-terized a～6.2-Mb sex-determining region on chromosome 3.Four potential male-specific genes,a partially duplicated DNA helicase gene(named MSDH)and three Ty3_Gypsy long terminal repeat retrotransposons(named MSTG1/2/3),were identified in the Y-linked area and considered to be strong candidate genes for sex determination or differentiation.Population genomic analysis showed that Guangdong accessions in China were genetically similar to Japanese accessions of mul-berry.In addition,genomic areas containing selective sweeps that distinguish domesticated mul-berry from wild populations in terms of flowering and disease resistance were identified.Our study provides an important genetic resource for sex identification research and molecular breeding in mulberry.