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Lecture

Spirochetes: Structure and Classification

Description

This lecture covers the structure and classification of spirochetes, including their cell wall characteristics, endoflagella, and phylogenetic classification. It also discusses specific genera like Treponema, Borrelia, and Leptospira, highlighting their habitats, mode of transmission, and associated diseases.

Instructor

Romain Zufferey

Official source

Ontological neighbourhood

Biology

Zoology: Topics in zoology

Related concepts (32)

Phylogenetic tree

A phylogenetic tree (also phylogeny or evolutionary tree) is a branching diagram or a tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. All life on Earth is part of a single phylogenetic tree, indicating common ancestry. In a rooted phylogenetic tree, each node with descendants represents the inferred most recent common ancestor of those descendants, and the edge lengths in some trees may be interpreted as time estimates.

Molecular phylogenetics

Molecular phylogenetics (məˈlɛkjᵿlər_ˌfaɪloʊdʒəˈnɛtɪks,_mɒ-,_moʊ-) is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree.

Spirochaete

A spirochaete (ˈspaɪroʊ-ˌkiːt) or spirochete is a member of the phylum Spirochaetota (-ˈkiːtiːz), (synonym Spirochaetes) which contains distinctive diderm (double-membrane) gram-negative bacteria, most of which have long, helically coiled (corkscrew-shaped or spiraled, hence the name) cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 3 and 500 μm and diameters around 0.09 to at least 3 μm. Spirochaetes are distinguished from other bacterial phyla by the location of their flagella, called endoflagella which are sometimes called axial filaments.

Borrelia

Borrelia is a genus of bacteria of the spirochete phylum. Several species cause Lyme disease, also called Lyme borreliosis, a zoonotic, vector-borne disease transmitted by ticks. Other species of Borrelia cause relapsing fever, and are transmitted by ticks or lice, depending on the species of bacteria. A few Borrelia species as Candidatus Borrelia mahuryensis harbor intermediate genetic features between Lyme disease and relapsing fever Borrelia.

Phylogenetics

In biology, phylogenetics (ˌfaɪloʊdʒəˈnɛtɪks,_-lə-) is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms.

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Phylogenetic Tree Construction

Covers the stages of building a phylogenetic tree using DNA sequences and the UPGMA method.

Exploring Evolution: Molecular Evidence and Mechanisms

Explores molecular evidence and mechanisms of evolution, including phylogenetic trees and protein comparisons.

Exploring Evolution: Molecular Insights and Protein Comparison

Explores evolution through enzymes, DNA models, and protein comparisons, discussing molecular insights and evolutionary mechanisms.

Constructing Phylogenetic Trees: UPGMA Algorithm

Covers the UPGMA algorithm for constructing phylogenetic trees and understanding genetic relationships.

Understanding Generative Models of Protein Sequences