scholarly journals The Mitragyna speciosa (Kratom) Genome: a resource for data-mining potent pharmaceuticals that impact human health

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Julia Brose ◽  
Kin H Lau ◽  
Thu Thuy Thi Dang ◽  
John P Hamilton ◽  
Lívia do Vale Martins ◽  
...  
Keyword(s):  
Data Mining ◽  
Chromosome Number ◽  
Chromosome Counting ◽  
Alkaloid Biosynthesis ◽  
Draft Assembly ◽  
Mitragyna Speciosa ◽  
Pharmaceutical Properties ◽  
Base Chromosome Number ◽  
Oxindole Alkaloids ◽  
Syntenic Analysis

Abstract Mitragyna speciosa (kratom) produces numerous compounds with pharmaceutical properties including the production of bioactive monoterpene indole and oxindole alkaloids. Using a linked-read approach, a 1,122,519,462 bp draft assembly of M. speciosa “Rifat” was generated with an N50 scaffold size of 1,020,971 bp and an N50 contig size of 70,448 bp that encodes 55,746 genes. Chromosome counting revealed that “Rifat” is a tetraploid with a base chromosome number of 11, which was further corroborated by orthology and syntenic analysis of the genome. Analysis of genes and clusters involved in specialized metabolism revealed genes putatively involved in alkaloid biosynthesis. Access to the genome of M. speciosa will facilitate an improved understanding of alkaloid biosynthesis and accelerate the production of bioactive alkaloids in heterologous hosts.

scholarly journals The Chemistry of Kratom [Mitragyna speciosa]: Updated Characterization Data and Methods to Elucidate Indole and Oxindole Alkaloids

2020 ◽  
Vol 83 (7) ◽  
pp. 2165-2177
Author(s):  
Laura Flores-Bocanegra ◽  
Huzefa A. Raja ◽  
Tyler N. Graf ◽  
Mario Augustinović ◽  
E. Diane Wallace ◽  
...  
Keyword(s):  
Mitragyna Speciosa ◽  
Oxindole Alkaloids

Karyotypes of Leptarrhena and Tanakaea (Saxifragaceae)

1984 ◽  
Vol 62 (4) ◽  
pp. 671-673 ◽  
Author(s):  
Douglas E. Soltis
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosomal Evolution ◽  
Conservative Nature ◽  
Chromosomal Data ◽  
Base Chromosome Number ◽  
Flavonoid Chemistry

In an attempt to clarify subtribal relationships in tribe Saxifrageae, chromosome numbers and karyotypes were determined for the two species comprising subtribe Leptarrheninae: Leptarrhena pyrolifolia and Tanakaea radicans. In both species 2n = 14, a common chromosome number throughout Saxifrageae. The two species have distinctive karyotypes that appear to differ in the centromeric positions of three pairs of chromosomes. These findings, in conjunction with earlier studies, demonstrate that genera of Saxifrageae often differ karyotypically. Leptarrhena exhibits considerable karyotypic similarity to genera of subtribe Saxifraginae characterized by a base chromosome number of x = 7. Chromosomal data, therefore, do not clearly differentiate subtribes Saxifraginae and Leptarrheninae. This observation is in agreement with evidence from paly-nology and flavonoid chemistry. Karyotypic studies continue to demonstrate the conservative nature of chromosomal evolution in tribe Saxifrageae.

Variation in pollen wall ultrastructure in New World Senecioneae (Asteraceae), with special reference to Packera

1997 ◽  
Vol 75 (5) ◽  
pp. 730-735 ◽  
Author(s):  
J. F. Bain ◽  
B. S. Tyson ◽  
D. F. Bray
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chromosome Number ◽  
Special Reference ◽  
New World ◽  
Pollen Wall ◽  
Wall Structure ◽  
Transmission Electron ◽  
Wall Ultrastructure ◽  
Base Chromosome Number

The structure of the pollen wall as revealed by transmission electron microscopy is presented for 34 species representing two subtribes and 12 genera of New World Senecioneae. The genus Packera (=aureoid Senecio), with the exception of Packera zimapanica, is characterized by the helianthoid wall structure. In light of these results, the disposition of the latter species requires review. The genera Robinsonecio and Telanthophora of the subtribe Tussilagininae also possess helianthoid pollen. All other taxa surveyed have senecioid pollen. So far as known no taxa exist within the tribe Senecioneae with a base chromosome number of n = 20 and helianthoid pollen. This suggests that the evolution of Packera may have involved hybridization between members of the two subtribes Senecionineae and Tussilagininae. Key words: Asteraceae, Packera, Senecioneae, pollen, TEM, systematics.

Meiotic abnormalities of Vaccinium ashei × Vaccinium darrowi hybrids

1984 ◽  
Vol 26 (2) ◽  
pp. 146-151 ◽  
Author(s):  
R. G. Goldy ◽  
P. M. Lyrene
Keyword(s):  
Chromosome Number ◽  
Key Words ◽  
Interspecific Hybridization ◽  
Unreduced Gametes ◽  
Meiotic Abnormalities ◽  
Vaccinium Ashei ◽  
Nucleolar Organizing Regions ◽  
Vaccinium Darrowi ◽  
Mother Cells ◽  
Base Chromosome Number

Meiosis was studied in pollen mother cells of three Vaccinium ashei (2n = 6x = 72) × Vaccinium darrowi (2n = 2x = 24) hybrids. Numerous irregularities were found, including 60 somatic chromosomes instead of the expected 48, two synezetic knots, two nucleolar organizing regions, lagging chromosomes at anaphase I and II, nonassociating chromosomes, meiotic asynchrony, micronuclei at telophase I and II, misaligned spindles, extra nucleoli, increased percentage of unreduced gametes, incomplete tetrads, and polyspory. Lagging chromosomes at anaphase I did not appear as univalents, but as bivalents. This suggests a base chromosome number for Vaccinium of x = 6, not x = 12.Key words: Vaccinium ashei, rabbiteye blueberry, Vaccinium darrowi, interspecific hybridization, cytogenetics, meiosis.

Chromosome Number Variation in the Myrtaceae and Its Taxonomic Implications

1979 ◽  
Vol 27 (5) ◽  
pp. 547 ◽  
Author(s):  
BL Rye
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Evolutionary Potential ◽  
The Family ◽  
Number Variation ◽  
Taxonomic Implications ◽  
Chromosome Number Variation ◽  
Australian Flora ◽  
Base Chromosome Number ◽  
Western Australian

New chromosome number determinations are reported for some 150 Western Australian species of the Myrtaceae. These include the lowest number (n = 5) so far recorded in the family and several newly recorded descending dysploid series. Dysploid chromosome numbers are far less common than the base chromosome number of n = 11 but parallel dysploid series have occurred in many groups and some have played a role in the origin of genera. Polyploidy has been successful at the intraspecific and interspecific levels but is of limited evolutionary potential. The cytoevolutionary trends in the Myrtaceae are examined in relation to taxonomic problems within the family and in relation to cytoevolution in the woody Australian flora as a whole. Smith- White's suggestion that a more natural generic classification in the Chamelauciinae could be obtained by grouping species with the same base chromosome numbers is found to be untenable.

Lectotypification of Syneilesis australis (Asteraceae: Senecioneae)

Phytotaxa ◽  
2016 ◽  
Vol 246 (2) ◽  
pp. 152
Author(s):  
Yu Hong ◽  
Lian-Sheng Xu ◽  
Chen Ren ◽  
Qin-Er Yang
Keyword(s):  
Chromosome Number ◽  
Perennial Herbs ◽  
Base Chromosome Number ◽  
Small Genus

Syneilesis Maximowicz (1859: 165) (Asteraceae: Senecioneae) is a small genus of seven species distributed mainly in China, Korea, and Japan (Chen & Nordenstam 2011). All its species are perennial herbs with 2 or 3 palmatisect stem leaves and a corymbose or paniculate synflorescence composed of several to many discoid capitula. The genus differs from its putative closest allies, including Miricacalia Kitamura (1936: 214), Parasenecio Smith & Small (1922: 93) and Sinacalia Robinson & Brettell (1977: 274), primarily by having a single cotyledon (Maximowicz 1859; Kitamura 1934) and a base chromosome number of x = 26 (Koyama 1961; Takeshita 1961; Arano 1964).

scholarly journals Stability in chromosome number and DNA content in synthetic tetraploids of Lolium multiflorum after two generations of selection

2017 ◽  
Vol 47 (2) ◽  
Author(s):  
Roselaine Cristina Pereira ◽  
Natália de Souza Santos ◽  
Fernanda de Oliveira Bustamante ◽  
Andrea Mittelmann ◽  
Vânia Helena Techio
Keyword(s):  
Chromosome Number ◽  
Dna Content ◽  
Genetic Stability ◽  
Chromosome Doubling ◽  
Lolium Multiflorum ◽  
Colchicine Treatment ◽  
Italian Ryegrass ◽  
Chromosome Counting ◽  
Two Generations ◽  
Viable Seeds

ABSTRACT: Chromosome doubling of Italian ryegrass genotypes ( Lolium multiflorum Lam.) adapted to the brazilian edaphoclimatic conditions is an important strategy used by breeders and aims to obtain more vigorous genotypes with better forage quality and disease resistance. The effectiveness of chromosome doubling can be measured by genetic stability and fertility rates of plants over generations. However, a common problem in the polyploidization process is the regeneration of mixoploid plants that have impaired fertility and genetic stability. The objective of this study was to verify if progenies of recently tetraploidized plants remain stable regarding DNA content and chromosome number, over two generations. Progenies of L. multiflorum plants artificially tetraploidized with colchicine treatment were evaluated. Chromosome counting and estimates of the DNA content were used to evaluate the genetic stability. The percentage of tetraploid plants (4X) increased over generations (18%, 34% and 91% in cycle 0, 1 and 2, respectively). All progenies identified as tetraploid by flow citometry showed variation in chromosome number (mixoploidy), but produced viable seeds. Results showed that stabilization in chromosome number and DNA content in tetraploidized plant progenies requires time and that the success of this procedure depends on a continuous and accurate screening and selection.

Karyology ofAconitumsubgenusLycoctonum(Ranunculaceae) from China, with a report of the new base chromosome number x = 6 in the genusAconitum

2016 ◽  
Vol 34 (4) ◽  
pp. 441-454 ◽  
Author(s):  
Yu Hong ◽  
Qi Gao ◽  
Yan Luo ◽  
Jiang-Ping Luo ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Base Chromosome Number

scholarly journals Genome Size, Chromosome Number and Morphological Data Reveal Unexpected Infraspecific Variability in Festuca (Poaceae)

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 906
Author(s):  
Gloria Martínez-Sagarra ◽  
Sílvia Castro ◽  
Lucie Mota ◽  
João Loureiro ◽  
Juan A. Devesa
Keyword(s):  
Chromosome Number ◽  
Genome Size ◽  
Ploidy Level ◽  
Morphological Data ◽  
Chromosome Counting ◽  
Ploidy Levels ◽  
2C Dna Content ◽  
Number Counts ◽  
First Time ◽  
Evolutionary Role

Polyploidy has played an important evolutionary role in the genus Festuca (Poaceae), and several ploidy levels (ranging from 2n = 2x = 14 to 2n = 12x = 84) have been detected to date. This study aimed to estimate the genome size and ploidy level of two subspecies belonging to the F. yvesii polyploid complex by flow cytometry and chromosome counting. The phenotypic variation of the cytotypes was also explored, based on herbarium material. The genome size of F. yvesii subsp. lagascae has been estimated for the first time. Nuclear 2C DNA content of F. yvesii subsp. summilusitana ranged from 21.44 to 31.91 pg, while that of F. yvesii subsp. lagascae was from 13.60 to 22.31 pg. We report the highest ploidy level detected for Festuca (2n = 14x = 98) and previously unknown cytotypes. A positive correlation between holoploid genome size and chromosome number counts shown herein was confirmed. The morphometric approach showed a slight trend towards an increase in the size of some organs consistent with the variation in the ploidy level. Differences in characters were usually significant only among the most extreme cytotypes of each subspecies, but, even in this case, the high overlapping ranges prevent their distinction.

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