Delta8 desaturase pathway, different from common delta6 desaturase pathway, is an alternate pathway of polyunsaturated fatty acids biosynthesis. Delta8-fatty acid desaturase is one of the key enzymes in delta8 desaturase pathway. Two specific fragments were separately cloned from genomic DNA and cDNA of Euglena gracilis by PCR with the primers designed according to the reported sequence. Comparison of the genomic and cDNA sequences revealed that there wasn't intron in this delta8-fatty acid desaturase gene. This gene has an open reading frame of 1 266 bp that encodes 421 amino acids. It is 6 bp longer than the reported gene sequence, and also showed certain difference from the reported sequence in the N-terminal. The recombinant expression plasmid pYEFD by subcloning delta8-fatty acid desaturase gene into the yeast-E. coli shuttle vector pYES2.0 was constructed and was transformed into the defective mutant INVSc1 of Saccharomyces cerevisiae by electrotransformation. The resulting strain YD8 harboring plasmid pYEFD was selected and was cultured in the induction medium with exogenous substrates omega6-eicosadienoic acid and omega3-eicosatrienoic acid for the expression of delta8-fatty acid desaturase gene. The results indicated that high level expressed As-fatty acid desaturase could convert omega6-eicosadienoic acid and omega3-eicosatrienoic acid to dihomo-gamma-linolenic acid and eicosatetraenoic acid with substrate conversion ratio 31.2% and 46.3%, respectively.
Amino Acid Sequence ; Cloning, Molecular ; Euglena gracilis ; enzymology ; Fatty Acid Desaturases ; biosynthesis ; genetics ; isolation & purification ; Genetic Vectors ; genetics ; Molecular Sequence Data ; Recombinant Proteins ; biosynthesis ; genetics ; Saccharomyces cerevisiae ; genetics ; metabolism

Objective:To observe the clinical phenotype of patients with CACNA1F gene variant. Methods:A retrospective clinical study. From January 1, 2022 to October 1, 2023, 36 patients with CACNA1F gene mutation-related eye diseases diagnosed by clinical examination and genetic testing in Changsha Aier Eye Hospital and Jinan Purui Eye Hospital were included in the study. All patients underwent best-corrected visual acuity (BCVA), medical optometry, fundus color photography, optical coherence tomography, full-field electroretinography (ERG), nystagmus examination, and genetic whole-exon sequencing. BCVA was performed using log visual acuity charts and converted to (logMAR). The nystagmus examination was performed using a helmet-mounted multifunctional video eye movement recording system. The clinical phenotypic characteristics were observed. Results:At total of 36 patients were male, aged was (6.69±5.26) years. There were 36 cases of myopia (38.89%, 14/36), and the spherical equivalent was (?3.01±4.84) D. There were 14 different genetic variants including 7 cases of pathogenic variants, 20 cases of suspected pathogenic variants and 9 cases of unknown pathogenic variants, respectively. logMAR BCVA was 0.67±0.27; 26 patients had optic nerve atrophy (72.22%, 26/36); 6 had optical nerve hypoplasia (16.67%, 6/36). Fundus pigment dysplasia with mild iris transillumination was found in 4 cases (11.11%, 4/36). There were 5 cases of foveal dysplasia (Thomas grade) 1 (13.89%, 5/36). In full-field ERG examination, the B-wave reduction of the maximum mixed reaction of dark adaptation showed a negative waveform, and the amplitude of the shock potential was seriously reduced. The main phenotypes were residual type (residual dark adaptation 0.01 reaction wave and bright adaptation 3.0 reaction wave, and the response decreased at 30 Hz to a double-peak wide wave), dominant type of bright adaptation decreased (all light adaptation extinguished, all dark adaptation extinguished), and total extinction type (all light adaptation extinguished). Among them, 10 cases presented with residual ERG (27.78%, 10/36), 8 cases with photopic reduced ERG (22.22%, 8/36) and 18 with extinguished ERG (50.00%, 18/36). Low amplitude and high frequency pendulum (PLAHF) nystagmus waverforms were found in 32 cases (88.89%, 32/36), head oscillation in 27 cases (75.00%, 27/36) and chin up abnormal head posture in 26 cases (72.22%, 26/36), respectively.Conclusions:CACNA1F Gene variant eye diseases had diverse clinical phenotype. Clinical phenotype of PLAHF nystagmus is closely related with CACNA1F gene variant eye disease.

Generic drugs account for more than 95% of the chemicals market in China, and their quality is directly related to the efficacy and safety of the people. The bioequivalence evaluation with pharmacokinetic parameters as the end point is the main content of the consistency evaluation of the quality and efficacy of generic drugs. Gut microbiota is considered to have an important influence on pharmacokinetics. This article reviewed the influence of gut microbiota on pharmacokinetics and analyzed its potential significance in the evaluation of the consistency of quality and efficacy of generic drugs.