The complete chloroplast genome of Asparagus densiflorus (Kunth) Jessop L.

Asparagus densiflorus (Kunth) Jessop L. is a horticultural plant widely cultivated in China. Herein, we reported the complete chloroplast (cp) genome of A. densiflorus from the genus Asparagus. The entire cp genome of A. densiflorus was 157,141 bp in length with one large single-copy region of 91,255 bp and one small single-copy region of 20,355 bp, separated by a pair of inverted-repeat regions of 45,531 bp. The GC content is 36.46% in this cp genome. A total of 134 genes were annotated including 90 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. The maximum-likelihood phylogenetic analysis showed that A. densiflorus was the most closely related to Asparagus cochinchinensis.

Base composition is the primary factor responsible for the variation of amino acid usage in zebra finch (Taeniopygia guttata).

In the present study, we carried out an examination of the amino acid usage in the zebra finch (Taeniopygia guttata) proteome. We found that tRNA abundance, base composition, hydrophobicity and aromaticity, protein second structure, cysteine residue (Cys) content and protein molecular weight had significant impact on the amino acid usage of the zebra finch. The above factors explained the total variability of 22.85%, 25.37%, 10.91%, 5.06%, 4.21%, and 3.14%, respectively. Altogether, approximately 70% of the total variability in zebra finch could be explained by such factors. Comparison of the amino acid usage between zebra finch, chicken (Gallus gallus) and human (Homo sapiens) suggested that the average frequency of various amino acid usage is generally consistent among them. Correspondence analysis indicated that base composition was the primary factor affecting the amino acid usage in zebra finch. This trend was different from chicken, but similar to human. Other factors affecting the amino acid usage in zebra finch, such as isochore structure, protein second structure, Cys frequency and protein molecular weight also showed the similar trends with human. We do not know whether the similar amino acid usage trend between human and zebra finch is related to the distinctive neural and behavioral traits, but it is worth studying in depth.