On Randy's website, I read:
Surprisingly, Jay Evans found that these genes are not upregulated in bees
from CCD colonies, even though the bees are full of pathogens! There are a
few potential explanations for this finding that come to mind:
1. The bee hemocytes are not recognizing the pathogens as foreign
(suppression of recognition systems, perhaps by viruses?).
2. The colonies could be protein-starved.
3. Something is suppressing the transcription of the genes, or their
translation to peptides. Note that viruses can do this very thing, which I
feel may be a big clue!
See: Sick Bees - Part 3: The Bee Immune System.
From 'Synergistic Parasite-Pathogen Interactions Mediated by Host Immunity
Can Drive the Collapse of Honey Bee Colonies":
See:
http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.100
2735
Page 6
Honeybee Immune System
To shed light on the alterations of the honeybee immune system associated
with Varroa-induced viral replication, we applied RNA-seq technology to
perform a transcriptomic analysis of adult bees collected from each
experimental colony in October, when the concurrent viral outbreak and the
bee mortality peak were observed. An immunosuppressive effect was evident in
bees collected from HIC, which was characterized by a significant
down-regulation of 19 immune genes [38]. The most pronounced effects were
observed on signalling molecules (e.g. dorsal-1A, a member of the protein
family NF-ęB, and serine proteases), while a relatively lower degree of
down-regulation was recorded for those involved in recognition of non-self
(e.g. AmSCR, scavenger receptors B5 and B7, C-type lectin 8) and for a few
components of immune signalling pathways (e.g. Hem, Tak1, SOCS) (Table 1,
Table S2). However, this immunosuppressive syndrome was associated with a
significant up-regulation of 6 immune genes, encoding both recognition
(PGRP-S2, NimC2, Eater-like) and signalling (serine proteases) molecules
(Table 1, Table S2), part of them playing a role in phagocytosis. The
differential expression of the genes which showed the most evident
alteration of their transcriptional profile was confirmed by means of a
Real-Time RT-PCR analysis of bee samples collected from the same colonies
(Figure S2); in particular, the absolute quantification of dorsal-1A, the
most down-regulated gene, with potential impact on several immune and stress
responses, confirmed the strong reduction of transcript level observed late
in the season in HIC (U = 2, n1 = 5, n2 = 5: P<0.05; Honeybee Immune System
To shed light on the alterations of the honeybee immune system associated
with Varroa-induced viral replication, we applied RNA-seq technology to
perform a transcriptomic analysis of adult bees collected from each
experimental colony in October, when the concurrent viral outbreak and the
bee mortality peak were observed. An immunosuppressive effect was evident in
bees collected from HIC, which was characterized by a significant
down-regulation of 19 immune genes [38]. The most pronounced effects were
observed on signalling molecules (e.g. dorsal-1A, a member of the protein
family NF-ęB, and serine proteases), while a relatively lower degree of
down-regulation was recorded for those involved in recognition of non-self
(e.g. AmSCR, scavenger receptors B5 and B7, C-type lectin 8) and for a few
components of immune signalling pathways (e.g. Hem, Tak1, SOCS) (Table 1,
Table S2). However, this immunosuppressive syndrome was associated with a
significant up-regulation of 6 immune genes, encoding both recognition
(PGRP-S2, NimC2, Eater-like) and signalling (serine proteases) molecules
(Table 1, Table S2), part of them playing a role in phagocytosis. The
differential expression of the genes which showed the most evident
alteration of their transcriptional profile was confirmed by means of a
Real-Time RT-PCR analysis of bee samples collected from the same colonies
(Figure S2); in particular, the absolute quantification of dorsal-1A, the
most down-regulated gene, with potential impact on several immune and stress
responses, confirmed the strong reduction of transcript level observed late
in the season in HIC (U = 2, n1 = 5, n2 = 5: P<0.05;
Randy, is this research the "big clue" you speak about?
I could have asked the question off-line, but I think many other BEE-liners
are interested in your answer.
Of course, feel free!
Kind regards,
Ghislain De Roeck
Belgium.
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