Tuesday, 24 June 2014
Whilst walking from Amberley to Arundel in West Sussex, UK, I spotted an abnormal growth on a leaf in a tree near the River Arun... I think it was a horse chestnut (Aesculus hippocastanum), but I do not remember now. There were a collection of these on a few leaves here and there. I suspect one would find some kind of mite inside... I left them undisturbed...
Also on the same tree was a curled leaf...
Friday, 7 September 2012
Just now I remembered a theory that I'd read somewhere a few years back.. that the caterpillar and the butterfly were once two separate insects, and somehow the two genomes mixed... (by virus? or microRNA? or endosymbiosis? or mimicry?) I had a quick search and discovered this blog article from BugTracks:
"modern metamorphosing insects arose when velvet worms (phylum Onychophora) somehow hybridized with primitive arthropods"read more: http://bugtracks.wordpress.com/2011/11/22/lynn-margulis/
"she somehow intuited that I would one day become obsessed with gall-making insects, and she showed me a chapter in a book she had edited in which it was hypothesized that fleshy fruits arose when gall-making insects happened to induce galls in the reproductive tissues of plants, so that the genetic coding for gallmaking was incorporated into the plant’s heritable genome."
and this paper: Caterpillars evolved from onychophorans by hybridogenesis
and this response: Caterpillars did not evolve from onychophorans by hybridogenesis
Lynn Margulis died of a stroke, 22 November, 2011.
Other interesting effects are Mimicry, Mimetism, Camouflage etc... changes forced through environmental pressures. ...
[Parthenogenesis - Hybridogenesis]
Thursday, 8 December 2011
Boechat, J. L., Rios, J. L., et al (2011) "Sick Building Syndrome (SBS) Among Workers of Two Buildings and Exposure to Indoor Fungal Allergens in Rio De Janeiro, Brazil"
Friday, 22 October 2010
Search the genome and view/download sequences. Read the tutorials on Gene Ontology - which describes the complete biology of individual gene products in any organism...
Other strains also available:
- Candida albicans WO-1
- Candida dubliniensis CD36
- Candida glabrata CBS138
- Candida guilliermondii ATCC 6260
- Candida lusitaniae ATCC 42720
- Candida parapsilosis CDC 317
- Candida tropicalis MYA-3404
- Debaryomyces hansenii CBS767
- Lodderomyces elongisporus NRLL YB-4239
The Saccharomyces Genome Database can be found here: http://www.yeastgenome.org/
What I am interested in, is Orthologs... between different species. Orthologs between the microbe and its host... .. and resources that enable one to compare two or more genomes... Genome Orthology? I am still in Year 2 level biology (at the age of 40 and after 20+ years interest)... but I see potential in comparing the ontologies of genes in different genomes...
Isolation and characterization of human orthologs of yeast CCR4–NOT complex subunits
Orthology between genomes of Brachypodium, wheat and rice
OrthologID: automation of genome-scale ortholog identification within a parsimony framework
Tuesday, 5 October 2010
Synchytrium endobioticum is a chytrid fungus (chytridiomycota - other species of which are known for their part in amphibian decline, esp. toads; and also maize- and alfalfa-attacking species...)
It affects potatoes and other uncultivated plants of the Solanum genus.
The zoospores of Synchytrium infect suitable epidermal cells on the host. The infected cells produce more zoospores, swell up, divide and surround the dividing zoospores... producing the characteristic wart.
Synchytrium endobioticum was added to the US Federal for agricultural plant pathogens: Public Health Security and Bioterrorism Preparedness and Response Act (June 12, 2002).
Tuesday, 30 March 2010
Oak Galls produced by the gallfly of the family Cynipidae. Can be found all over UK... young Oaks appear to be more susceptible than older. The acorn has been infected by a larvae which alters the normal growth of the acorn. The flesh of the gall is less tough than an acorn would be and is larger and more rounded.
[Photos by Oliver (cc)]
Wednesday, 13 August 2008
Genus: Saccharomyces (from latin, 'sugar mold')
Also known as Brewer's Yeast, Ale Yeast, Baker's Yeast, Budding Yeast
This species is the main source of nutritional yeast and yeast extract.
It is estimated that yeast shares 23% of its genome with that of humans.
Saccharomycetes is the most studied of the yeasts due to its availability and its being around for thousands of years...
Six Human RNA Polymerase Subunits Functionally Substitute for Their Yeast Counterparts
(view PDF at American Society of Microbiology)
McKune, Keith; Moore, Paul A.; Hull, Melissa W.; Woychik, Nancy A.
MOLECULAR AND CELLULAR BIOLOGY, Dec. 1995, p. 6895–6900
This study looks at Saccharomyces cerevisiae pol II
"Immunoprecipitation of the cell extracts from yeast cells containing either of the human subunits that function in place of their yeast counterparts in vivo suggested that they assemble with the complete set of yeast RNA polymerase II subunits. Overall, a total of six of the seven human subunits tested previously or in this study are able to substitute for their yeast counterparts in vivo, underscoring the remarkable similarities between the transcriptional machineries of lower and higher eukaryotes."
Tuesday, 12 August 2008
"Our results reinforce the hypothesis that C. albicans is one of the triggers to both exacerbation and persistence of psoriasis."
Waldman, A., A. Gilhar, L. Duek, and I. Berdicevsky. 2001. Incidence of Candida in psoriasis—a study on the fungal flora of psoriatic patients. Mycoses 44:77–81.
This does not mean that C.albicans is the cause of Psoriasis. Psoriasis appears to have several causal agents and quite possibly two patients with psoriasis do not share the same causal agent. Other agents are trauma to the skin, streptococcal infections, and even lithium, antimalarial agents, NSAIDs and angiotensin-converting enzyme inhibitors can exacerbate or possibly induce psoriasis...
C.albicans has only been hinted at as existing more in Psoriatic patients than those with dermatitis or normal but it is not a hugely significant difference and thus has been declared irrelevant by one later study in 2007
[Leibovici et al, 2007. Prevalence of Candida on the tongue and intertriginous areas of psoriatic and atopic dermatitis patients. Mycoses 51:63-66]
The photo here is from Hainault Forest's website which shows many other examples of galls caused by various agents including fungi, insects etc.
Taphrina pruni transforms the ovaries of plums into hollow galls without a stone - hence the name 'Pocket Plum'.
[photos from The Fifth Kingdom Chapter 4b and Backyard Nature]
In Peach Leaf Curl the leaves become thickened, distorted and turn yellow or reddish in colour, later causing the leaves to turn brown, dusty with ascospores and to fall. Taphrina deformans also affects the flowers and peach fruits, causing them either to drop early or become crooked at the stem or develop reddish to purple, wart-like deformities on the fruit surface.
Peach Leaf Curl (Kearnseyville Tree Fruit Research and Education Centre, West Virginia University)
"The mycelium enters the leaf and works its way among the leaf's cells. At this time, while a lot of complex genetic stuff is going on inside the mycelium cells, something causes the leaf's cells to elongate, causing twisting and blistering of the leaf. Eventually certain cells of the mycelium begin enlarging, growing to such an extent that they cause the leaf's cuticle, or "skin," to burst. Now these special, enlarged mycelium cells work themselves onto the leaf's surface and form a very thin surface called the hymenium consisting of stacked-together, clublike asci. The asci rupture, releasing ascospores, and now the life cycle starts over."
[from Backyard Nature]
So... the question that I would like to ask is ... If C.albicans is eluding the immune system, then isn't the immune system compromised? Does the immune system have to be compromised already for infection by C.albicans to occur? The following are quotes from a paper investigating the effect of the yeast and hyphal forms of C.albicans on differentiating monocytes in the human immune system.
"A special feature of C. albicans that is likely to play an important role in evasion of the immune response is the morphological transition from a unicellular yeast (Y) form to an elongated, multinucleate hyphal or mycelial form through the critical stage of germ tube (GT) formation. Conversion from the Y form to the GT form is strictly associated with virulence, as demonstrated by the fact that several mutants with the hypha-specific genes deleted, as well as wild-type strains unable to grow into the mycelial form, invariably have low systemic pathogenicity"Candida albicans Yeast and Germ Tube Forms Interfere Differently with Human Monocyte Differentiation into Dendritic Cells: a Novel Dimorphism-Dependent Mechanism To Escape the Host's Immune Response
"The different modulatory effects exerted by Y and GT forms of C. albicans on differentiating monocytes may be a key phenomenon that contributes to an explanation of the intriguing paradox that distinguishes this fungus, as represented by its persistence in some body compartments as a commensal yeast or as pathogen hyphae despite the presence of vigorous cellular and humoral systemic immune responses."
"Thus, the differentiation of human monocytes into DCs appears to be tunable and exploitable by C. albicans to elude immune surveillance."
Antonella Torosantucci, Giulia Romagnoli, Paola Chiani, Annarita Stringaro, Pasqualina Crateri, Sabrina Mariotti, Raffaela Teloni, Giuseppe Arancia, Antonio Cassone, and Roberto Nisini
Infect Immun. 2004 February; 72(2): 833–843. doi: 10.1128/IAI.72.2.833-843.2004.
[photo by James Lindsey@Wikimedia Commons]
Birch Witches' Brooms are masses of densely branched small twigs that resemble a witch's broom stuck in the tree's canopy. Witches' Brooms can be induced by various parasites including Taphrina betulina Rostrup. (Current thinking believes gall inducing phytoplasma may be responsible for some witches' brooms.)
Witches' Broom on Wikipedia
Birch Leaf Curl is induced by a Taphrina betulae (Fckl.) Johans. infection.
It has been found that Taphrina betulina infections in White Birch (Betula pubescens) trees cause reduced growth (by an average of 25%) and vigour, and 'Witches' Broom' growths (pictured here), the number and sizes of which correlate to the DBH (diameter at breast height), but not to the reductions in height and vigour .
1. (from Abstract) The effects of Taphrina betulina infection on growth of Betula pubescens, Y. A. Simmons and S. Woodward, European Journal of Forest Pathology, 2007 - Vol 24, Issue 5, p.277-286
Taphrina is fungal genus within the Ascomycota that causes leaf and catkin curl diseases and witch's brooms of certain flowering plants. One of the more commonly observed species causes peach leaf curl.
Taphrina typically grow as yeasts during one phase of their life-cycles, then infect plant tissues in which typical hyphae are formed, and ultimately they form a naked layer of asci on the deformed, often brightly pigmented surfaces of their hosts.
No discrete fruitbody is formed outside of the gall-like or blister-like tissues of the hosts. The asci form a layer lacking paraphyses, and they lack croziers. The acospores frequently bud into multiple yeast cells within the asci.
Phylogenetically, Taphrina is a member of a basal group within the Ascomycota, and type genus for the subphylum Taphrinomycotina, the class Taphrinomycetes, and order Taphrinales.
Some common Taphrina species:
- Taphrina betulina Rostrup - Birch Witches' Broom
- Taphrina pruni Tul. - Pocket Plums (gall affecting fruit on Blackthorn)
- Taphrina carpini - on Hornbeam
- Taphrina deformans - Peach Leaf Curl
- Taphrina caerulescens - Oak Leaf Blister
- Taphrina sacchari - Maple leaf blister
- Taphrina populina - Poplar